Peter is 8 years younger than Alex. In 9 years time, the sum of their ages will be 76 . How old is Alex now?

Answer:

w = 5

y = 4

Step-by-step explanation:

w + y = 9

3w - y = 11 ( + )

________

4w + 0 = 20

4w = 20

w = 20 / 4

w = 5

Substitute w = 5 in eq. w + y = 9,

w + y = 9

5 + y = 9

y = 9 - 5

y = 4

Answer:

125

Step-by-step explanation:

We know that the side length is 5, and the formula for the volume of a cube is the side length cubed. Therefore, 5 cubed is equal to the volume.

A value cubed is equal to a value multiplied by itself twice. Therefore, 5 cubed is equal to 5 * 5 * 5. This is equal to 125

Answer:

125

Step-by-step explanation:

Decimals start at tenths, then hundredths, then thousandths, and so on. When we round, we look at the place value that is one smaller than the one we want to round to.

So, let's take a look at the thousandths place in 0.485. The value in the thousandths place is 5. When rounding, if the value is 5 or over we round up and if the value is 4 or lower we round down. Since the value in the thousandths place is 5, we will round the hundredths place up one.

0.485 rounded to the nearest hundredth is 0.49

Hope this helps!

Answer:

0.49

Step-by-step explanation:

[tex]0<x<5=[/tex] Round down

[tex]x\geq5=[/tex] Round up

In this case, it's a round up, so the answer would be...

0.49

Hope this helped! Please mark brainliest!

Answer:

49+m

Step-by-step explanation:

37+12 = 49

49 + m is the total time Katherine takes.

Answer:

[tex]\boxed{\sf cos2A =\dfrac{\sqrt3}{2}}[/tex]

Step-by-step explanation:

Here we are given that the value of sinA is √3-1/2√2 , and we need to prove that the value of cos2A is √3/2 .

Given :-

• [tex]\sf\implies sinA =\dfrac{\sqrt3-1}{2\sqrt2}[/tex]

To Prove :-

•[tex]\sf\implies cos2A =\dfrac{\sqrt3}{2} [/tex]

Proof :-

We know that ,

[tex]\sf\implies cos2A = 1 - 2sin^2A [/tex]

Therefore , here substituting the value of sinA , we have ,

[tex]\sf\implies cos2A = 1 - 2\bigg( \dfrac{\sqrt3-1}{2\sqrt2}\bigg)^2 [/tex]

Simplify the whole square ,

[tex]\sf\implies cos2A = 1 -2\times \dfrac{ 3 +1-2\sqrt3}{8} [/tex]

Add the numbers in numerator ,

[tex]\sf\implies cos2A = 1-2\times \dfrac{4-2\sqrt3}{8} [/tex]

Multiply it by 2 ,

[tex]\sf\implies cos2A = 1 - \dfrac{ 4-2\sqrt3}{4} [/tex]

Take out 2 common from the numerator ,

[tex]\sf\implies cos2A = 1-\dfrac{2(2-\sqrt3)}{4} [/tex]

Simplify ,

[tex]\sf\implies cos2A = 1 -\dfrac{ 2-\sqrt3}{2}[/tex]

Subtract the numbers ,

[tex]\sf\implies cos2A = \dfrac{ 2-2+\sqrt3}{2} [/tex]

Simplify,

[tex]\sf\implies \boxed{\pink{\sf cos2A =\dfrac{\sqrt3}{2}} } [/tex]

Hence Proved !

Answer:

Option A, 7b

Step-by-step explanation:

a/b=7/2

or, 2a=7b

Answered by GAUTHMATH

Answer:

A)7b

its yr ans.

hope it helps.

Hello!

√32 × √24 =

= √768 =

= 16√3

Good luck! :)

Answer:

16×sqrt(3)

Step-by-step explanation:

what full square numbers are factors in the numbers under the square root that we can pull out ?

and then multiply the rest under the square root and possibly repeat one more time.

32 = 16×2

16 is a great square number.

in 24 we find 4 as the largest square factor.

so,

sqrt(32)×sqrt(24) = sqrt(16×2)×sqrt(4×6) =

= 4×sqrt(2)×2×sqrt(6) = 8×sqrt(2×6) = 8×sqrt(12) =

= 8×sqrt(4×3) = 8×2×sqrt(3) = 16×sqrt(3)

Answer: 130 liters

Step-by-step explanation:

1 hectoliter = 100 liters

1.3 hectoliters = 1.3 · 100 = 130 liters

Answer:

Part 1)

1) Sylvia' process was incorrect. In her last step, when she multiplied 0.88 by 10, she also need to divide exponent by 10.

2) Dylan is perfectly correct.

3) Ethan's process was also incorrect. Instead of subtracting the exponents, he added them.

Part 2)

Only Skyler's approach was incorrect. When Skyler acquired (3⁶)ˣ = 9, he made the error of setting the exponent on the left to the value on the right.

Step-by-step explanation:

Part 1)

We want to simplify the expression:

[tex]\displaystyle \frac{3.61\times 10^{-11}}{4.1\times 10^7}[/tex]

We can divide. Recall that xᵃ / xᵇ = xᵃ ⁻ ᵇ. Hence:

[tex]\displaystyle =0.88\times 10^{-11-7}=0.88\times 10^{-18}[/tex]

In scientific notation, the coefficient is always between 1 or 10.

So, we can multiply 0.88 by 10. To keep the equality, we need to divide 10⁻¹⁸ by 10. Hence:

[tex]\displaystyle =0.88(10)\times \frac{10^{-18}}{10}[/tex]

(You can see that the 10s can cancel out, giving us our original expression.)

Simplify. Thus:

[tex]\displaystyle \frac{3.61\times 10^{-11}}{4.1\times 10^7} = 8.8\times 10^{-19}[/tex]

Therefore, as we can see:

1) Sylvia' process was incorrect. In her last step, when she multiplied 0.88 by 10, she also need to divide exponent by 10.

2) Dylan is perfectly correct.

3) Ethan's process was also incorrect. Instead of subtracting the exponents, he added them.

Part 2)

Reviewing their work, we can see that only Skyler's approach was incorrect.

729 is indeed 3⁶. However, when Skyler acquired (3⁶)ˣ = 9, he made the error of setting the exponent on the left to the value on the right.

Both Robert and Kevin are correct, having set each exponent equal to each other after their bases are equivalent and solving for x.

Answer:

8. 36

Step-by-step explanation:

8.

The diameter of the square is x=[tex]\sqrt{6^{2} +6^{2} }\\[/tex] = [tex]\sqrt{72}[/tex] = 6 [tex]\sqrt{2}[/tex]

The diameter of the square is the diameter of the circle, therefore the radius of the circle is r = 6 [tex]\sqrt{2}[/tex]/2 = 3[tex]\sqrt{2}[/tex]

The area of the shaded region, which is a circle is A= π[tex]r^{2}[/tex] =  π[tex](3\sqrt{2} )^{2}[/tex] = 36π

SOLUTION:

10•10= 100

Answer:

-1/2

Step-by-step explanation:

Answer:

Mathematics is very important in a small business is because when you make money transactions with other people you need to know how to count money correctly and your calculations can’t be wrong. When we sign up for jobs like police, or firefighter, we need to use math. Math helps us solve real-world problems.

Step-by-step explanation:

These are indeed equivalent, and this identity is one of DeMorgan's laws.

The 6th column is the negation of the 5th column. For example, the first row says

not p or q

is true (T), so the negation would be false (F). The 5th column reads {T, F, T, T}, so the next column should be {F, T, F, F}.

Then in the 7th/last column, you are checking the truth value of the statement

p and not q

For example, in the first row, both p and q are true (T). This means (not q) is false, so (p and not q) is false (F). The last column should end up reading {F, T, F, F}, same as the previous column.

Answer:

[tex]\frac{29}{35}[/tex] ft (29/35 ft)

Step-by-step explanation:

Perimeter: [tex]2w+2l[/tex]

[tex]2(\frac{1}{5})+2(\frac{3}{14})=\frac{2}{5} +\frac{6}{14}[/tex]

Since [tex]\frac{6}{14} = \frac{3}{7}[/tex], the LCD would be 35

New equation: [tex]\frac{14}{35} +\frac{15}{35} =\frac{29}{35}[/tex]

[tex]\frac{29}{35}[/tex]

Hope this helped! Please mark brainliest :)

Answer:

144

Step-by-step explanation:

To Find :-

Solution :-

We have ,

> 1/8 , 2/9 , 3/12 .

The denominator of the fractions are ,

> 8 , 9 , 12

The LCM of 8,9,12 will be ,

2 | 8 , 9 , 12

2 | 4 , 9 , 6

2 | 2 , 9 , 3

3 | 2 , 3 , 1

Therefore , LCM will be ,

> 2⁴ × 3² = 16 × 9 = 144

Answer:

Step-by-step explanation:

the first and last choices look good  

Answer:The zeros are 7 and 5, because y=(x-7)(x-5)

Step-by-step explanation:

Answer:

13⅗ is the answer of your quest

Answer:

1 mile per 10 minutes

Step-by-step explanation:

Answer:

False

Step-by-step explanation:

A field book is a private notepad used by a surveyor to record measurements and notes.

Basically, the size of a field book is 200 millimeters × 120 millimeters (20 centimeters × 12 centimeters) and it's typically opened lengthwise. There are two (2) main types of field book and these includes;

I. Double-line field book.

II. Single-line field book.

As a general rule, it's best that all findings, entries (notes) and observations are recorded or made into a field book after each and every measurement have been taken by a surveyor.

In conclusion, a field book is considered to be a legal document used by surveyors to keep records of accomplished field work or work done in the field. Thus, it's not a private notepad used by a surveyor to transcribe notes.

Answer:

False

Step-by-step explanation:

A field book is a private notepad used by a surveyor to transcribe notes and is not considered a legal document is False.

Answer:

Lucy must walk up 80 steps to reach the 6th floor.

Step-by-step explanation:

Since Michael was 1.0 meters tall, and could only reach up to the 1st floor lift button, and from the 1st floor, he had to walk up 100 steps to reach the 6th floor; while Vinh was 1.4 meters tall, and could reach the 5th floor button, and he had to walk up 20 steps to reach the 6th floor; If Lucy was 1.1 meters tall, to determine how many steps did she have to walk up to reach the 6th floor, the following calculation must be performed:

1 = 100

1.4 = 20

1.4 - 1 = 100 - 20

0.4 = 80

0.1 = X

0.1 x 80 / 0.4 = X

20 = X

100 - 20 = 80

Therefore, Lucy must walk up 80 steps to reach the 6th floor.

Answer:

[tex]x=\frac{5}{2} \\y=5[/tex]

( 5/2, 2 )

Step-by-step explanation:

Solve by substitution method:

[tex]2x+5=10\\\2x+3y=20[/tex]

Solve [tex]2x+5=10[/tex] for [tex]x[/tex]:

[tex]2x+5=10[/tex]

[tex]2x=10-5[/tex]

[tex]2x=5[/tex]

[tex]x=5/2[/tex]

Substitute [tex]5/2[/tex] for [tex]x[/tex] in [tex]2x+3y=20[/tex]:

[tex]2x+3y=20[/tex]

[tex]2(\frac{5}{2} )+3y=20[/tex]

[tex]3y+5=20[/tex]

[tex]3y=20-5[/tex]

[tex]3y=15[/tex]

[tex]y=15/3[/tex]

[tex]y=5[/tex]

∴ [tex]x=\frac{5}{2}[/tex] and [tex]y=5[/tex]

hope this helps....

Answer:

wheres the underline pls let me know what is underlined ill answer it on comment

Step-by-step explanation:

Recall that

[tex]1 + \tan^2 x = \sec^2 x[/tex]

and

[tex]\dfrac{d}{dx}(\tan x) = \sec^2 x[/tex]

so that

[tex]\displaystyle \int \tan^2 x = \int (\sec^2 x - 1)dx[/tex]

[tex]\:\:\:\:\:\:\:\:\:=\int \sec^2 xdx - \int dx[/tex]

[tex]\:\:\:\:\:\:\:\:\:=\tan x - x + C[/tex]

where C is the constant of integration.

Answer:

95%: (3278.354 ; 3270.083)

99% : (3221.646 ; 3278.354)

Step-by-step explanation:

Given :

Sample size, n = 12

Mean, xbar = 3250

Sample standard deviation = √1000

The 95% confidence interval :

Mean ± Margin of error

Margin of Error = Tcritical * s/√n

Tcritical at 0.05, df=12-1 = 11 ;

Tcritical at 95% = 2.20

Hence,

Margin of Error = (2.20 * √1000/√12) = 20.083

Confidence interval : 3250 ± 20.083

Lower boundary = 3250 - 20.083 = 3229.917

Upper boundary = 3250 + 20.083 = 3270.083

2.)

The 99% confidence interval :

Mean ± Margin of error

Margin of Error = Tcritical * s/√n

Tcritical at 0.01, df=12-1 = 11 ;

Tcritical at 99% = 3.106

Hence,

Margin of Error = (3.106 * √1000/√12) = 28.354

Confidence interval : 3250 ± 28.354

Lower boundary = 3250 - 28.354 = 3221.646

Upper boundary = 3250 + 28.354 = 3278.354

Answer:

perimeter=9cm

Area=2cm^2

step by step explanation:

Firstly solve the sides that don't have figures using trigonometry

#1..sin15°=opposite/hypotenuse

sin15=opposite/4

opposite=sin15×4

=1.035, round off to 1cm

Then find the value of the base

tan15=opposite/adjacent

tan15=1/adjacent

1=tan15adjascent

1/tan15=adjacent

adjacent or base=3.7 round off to 4cm

After finding these values find the perimeter

p=side+side+side

p=4cm+4cm+1cm

p=9cm

Find the area

1/2bh

1/2×4×1

A=2cm2

Answer:

Step-by-step explanation:

Let AC = x

AB - AC = 4 cm

AB = 4 +x  ----------------(I)

Pythagorean theorem

AB² + AC² =BC²

(4 + x)² + x² = 9²

Use the identity (a + b)² = a² + 2ab + b² where a = 4 & b = x

4² +2*4*x  +x² + x²= 81

16 + 8x + 2x² = 81

2x² + 8x + 16 - 81 = 0

2x² + 8x - 65= 0

a = 2 ; b = 8 ; c = -65

D = b² - 4ac

   = 8² - 4*2*(-65)

  = 64 +  520

D = 584

√D = √584 = 24.16

[tex]x=\frac{-b+\sqrt{D}}{2a} \ or \ x =\frac{-b-\sqrt{D}}{2a}\\\\x= \frac{-8+24.16}{2*2} \ or \ x = \frac{-8-24.6}{2*2}[/tex]   {Ignore this as it is negative.}

x = 16.16/4

x = 4.04

AC = 4.04 Cm

AB = 4 + 4.04 = 8.04 cm

Area of triangle ABC = [tex]\frac{1}{2}* base * height[/tex]

                                   [tex]=\frac{1}{2}*4.04 *8.04\\\\= 2.02 * 8.04[/tex]

                                   = 16.24 sq.cm

Answer:

Step-by-step explanation:

l -> length

b -> width

h -> height

Find the area of four walls and ceiling. then subtract the area of four windows and a door form that area.

Area of four walls + ceiling = 2( lh + bh) +lb

 = 2*(20*5 + 15*5) + 20*15

= 2( 100 + 75) + 300

= 2* 175 + 300

= 350 +300

= 650 sq m

Area of window = 2 *3 = 6 sq.m

Area of four windows = 4*6 = 24 sq.m

Area of door = 2 * 1 =  2 sq.m

Area of four walls excluding 4 windows and door = 650 - 24 - 2 = 624 sq.m

Cost of painting = 624 * 6.50

                          = $ 4056

Answer:  1950 dollars to paint the ceiling only (ignoring the walls)

The cost to paint the walls only is 2106 dollars.

The cost to paint the walls and ceiling is 4056 dollars.

==================================================

Explanation:

It seems a bit strange how your teacher mentions the windows and doors, but then asks about the ceiling only. Perhaps this is a red herring, but I'm not sure.

Anyway, to directly answer the question, we'll need to find the area of the ceiling first. The ceiling is a rectangle of dimensions 20 m by 15 m, so its area is 20*15 = 300 square meters.

Since paint costs 6.50 dollars per square meter, the total cost for the ceiling alone is 6.50*300 = 1950 dollars

If your teacher only cares about the ceiling, then you can stop here (and ignore the next section below).

---------------------------

If you wanted to find the cost to paint the walls, then we need to find the area of the walls.

For now, ignore the windows and door. Two opposite walls have area of 20*5 = 100 m^2 each. That accounts for 2*100 = 200 m^2 of wall area so far.

The other pair of opposite walls have area 15*5 = 75 m^2 each. That's another 2*75 = 150 m^2 of wall area.

In all, the total wall area without considering the windows or door is 200+150 = 350 m^2.

Now we consider the windows. Each window is 2 m by 3 m, yielding an area of 2*3 = 6 m^2. Four such windows have a total area of 4*6 = 24 m^2.

The door is 2 m by 1 m, so its area is 2*1 = 2 m^2

We'll subtract the wall area and the combined window+door areas to get

wallArea - windowArea - doorArea = 350-24-2 = 324

So after accounting for the windows and door, the amount of wall to paint is 324 m^2, which leads to a cost of 6.50*324 = 2106 dollars.

Therefore, painting the walls and ceiling gets us a total cost of 1950+2106 = 4056 dollars

This section is entirely optional if your teacher only cares about the ceiling.