If a + b = 2 and a - b = -4 what is the value of ab A. 5 B. -5 c.3 D. -3​

Answers

Answer 1

Answer:

D

Step-by-step explanation:

Given the 2 equations

a + b = 2 → (1)

a - b = - 4 → (2)

Add the equations term by term to eliminate b

2a + 0 = - 2

2a = - 2 ( divide both sides by 2 )

a = - 1

Substitute a = - 1 into (1) and solve for b

- 1 + b = 2 ( add 1 to both sides )

b = 3

Then

ab = - 1 × 3 = - 3 → D

Answer 2

Answer:

option d

Step-by-step explanation:

a+b=2. ,. a-b = -4

a= 2-b

substituting values, we get

(2-b) - b = -4

2 -b -b =-4

2 -2b =-4

-2b = -4-2

2b= 6

b =3

a = 2-3

a= -1

ab = 3×-1

ab = -3


Related Questions

Find angle C!!!!! See the image below! I need this answer fast

Answers

Answer:

55

Angle C is a inscribed angle of the of Arc Ba.

CA is the diameter so that means Arc BA equal 110 becuase

110+70=180.

Angle C is half of Arc BA so Angle C is

[tex]55[/tex]

Each figure shows a triangle with one of its angle bisectors.
12) 22 - 38°. Find mZTRS.

Answers

Answer:

76 degrees

Step-by-step explanation:

this special line is an angle bisected.

that means it splits the angle at its starting point in 2 halves. as these names indicate, both parts are of equal size (half of the general angle).

we know one part (2) of this split angle : 38 degrees.

the other part (1) had to be equally sized : 38 degrees.

so, the total angle at point R is the sum of both split angles:

TRS = 38+38 = 76 degrees.

In this addition problem, each letter stands for a different digit.
A
A
+ B B
-------------------
C C C

Find the value of A + B + C?

Answers

The answer is a+b+c equals abc

list the set of ordered pairs that had a domain that consists of multiples of 3 from -3 to 15

Answers

Answer:

Multiple of 3 from -3 to 15 are:-

3, 6, 9, 12 , 15

hope it is helpful to you ☺️

find the value of x. round to the nearest tenth.

Answers

Answer:

x = 26.4

Step-by-step explanation:

Hi there!

What we need to know:

Basic trigonomic ratios (θ is the reference angle):

Sine θ = opposite / hypotenuseCosine θ = adjacent / hypotenuseTangent θ = opposite / adjacent

Given the diagram, we can see that the reference angle is x. We are also given the hypotenuse (9) and the opposite side length (4). With the opposite and the hypotenuse, we know that we need to use the sine ratio:

sin(x) = 4/9

To solve for an angle given the side lengths, we use the inverse functions:

x = sin^-1 (4/9)

x = 26.4

I hope this helps!

can i get help lost on this one

Answers

[tex]\cfrac{\frac{a}{b}}{\frac{c}{ d}}\implies \cfrac{a}{b}\cdot \cfrac{ d}{c} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \cfrac{~~\frac{3x^2-3}{x^2+3x}~~}{\frac{x+1}{x(x+3)}}\implies \cfrac{3x^2-3}{x^2+3x}\cdot \cfrac{x(x+3)}{x+1}\implies \stackrel{\textit{common factoring}}{\cfrac{3(x^2-1)}{~~\begin{matrix}x (x+3) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}}\cdot \cfrac{~~\begin{matrix} x (x+3) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}{x+1}[/tex]

[tex]\textit{keeping in mind that}\qquad x^2-1\implies x^2-1^2\implies (x-1)(x+1) \\\\\\ \cfrac{\stackrel{~~\textit{difference of squares}}{3(x^2-1^2)~\hfill }}{x+1}\implies \cfrac{3(x-1)~~\begin{matrix} (x+1) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}{\begin{matrix} (x+1) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}}\implies 3(x-1)[/tex]

Please helppppppp meeee

Answers

Answer:

angle K is 30 degrees

Step-by-step explanation:

A triangle adds up to 180 degrees. since LM and KM are congruent angle L and M are both 75 degrees each you subtract from 180 and you get 30 degrees

Someone pls help me :p

Which is an irrational number?
It’s question number 5 pls

Answers

Answer:

A.

Step-by-step explanation:

An irrational number is a number that goes on forever without repeating. The square root of 2 does exactly this.

Luca works at an appliance store. He recently sold 12 appliances, 6 of which were
dishwashers. What is the experimental probability that the next appliance Luca sells will be a
dishwasher?
Write your answer as a fraction or whole number.

Answers

Answer:

1/2

Step-by-step explanation:

Answer:

0.50

Step-by-step explanation:

6 out of the total 12 appliances sold were dishwashers, so the experimental probability that the next appliance sold will be a dishwasher is 6/12, or 1/2, or 0.50.

Supriya is decorating her bedroom. She plans to hang strings of twinkle lights all the way around her walls. She measures the walls and finds she will need 36meters of lights.(area,lenght,or perimeter)

Answers

Answer:

Perimeter

Step-by-step explanation:

Required

What does 36m represent?

From the question, we understand that the 36m is the measurement of the wall.

This, in other words, means the perimeter of the wall.

Hence, Supriya measured the perimeter

Ahhh please help I’m having a hard time with this( ̄^ ̄)ゞ

Answers

Answer:

A  x+y

B x+0 + (y+0)

Step-by-step explanation:

(x+0) + y+0

Adding 0

x+y

Changing the order of the parentheses

x+0 + (y+0)

is still the same

Help pls!! this is a presentation I’m doing in class and I NEED this completed rn, ASAP!!! . What I need is just the answers for the picture below and I NEED the explanation to all of them, and if you can pls try to give a similar example to these and solve it or what did u use to solve it. (Only 1 example that is similar) Thank you so much!

Answers

Answer:

Step-by-step explanation:

∠ADC = 90°

∠ADB + ∠BDC = 90

20 + ∠BDC = 90

       ∠BDC = 90 - 20 = 70

            ∠BDC = 70°

16) ∠PSR = ∠PSQ  +∠QSR

              = 60 + 10

              = 70

18) ∠PSR = 130

∠PSQ + ∠QSR = 130

90+ ∠QSR = 130

       ∠QSR = 130 - 90

∠QSR = 40

19)∠ADC = ∠ADB + ∠BDC

               = 120 +20

               = 140

20) ∠PSR  = 125

15. 70° because a right angle is 90° and we have the angle of ADB which is 20°. So 90°-20°=70°.

16. 70° because angle PSQ is 60° and angle QSR is 10°. So 60°+10°=70°.

17. 55° because it says it in the explanation. I assume this is a typo and they meant to ask the measurement of ADC and in that case it would be 130° because angle ADB is 75° and angle BDC is 55°. 75°+55°=130°.

18. 40° because angle PSQ is a right angle which means it's 90°. So 130°-90°=40°.

19. 140° because angle ADB is 120° and angle BDC is 20° so 120°+20°=140°.

20. 125° because again it's in the explanation. But if it's a typo and they meant what is the measurement of PSQ then it is 50° because PSR is 125° and QSR is 75° so 125°-75°=50°.

Hope this helps! :)

Cynthia has $2.15 worth of change in her pocket. She has three more nickels than quarters and twice as many dimes as quarters. How many of each type coin has she?

Answers

Answer:

7 nickles

8 dimes

4 quarters

Step-by-step explanation:

q

d = 2q

n = q+3

25q + 10d + 5n = 215

25q + 10(2q) + 5(q + 3) = 215

25q + 20q + 5q - 15 = 215

50q = 200

q = 4

d = 2q = 8

n = q + 3 = 7

Pls help me I don’t get it

Answers

Answer:

15.71cm

Step-by-step explanation:

perimeter of a semi circle=1/2(πdiameter)

1/2(3.142×10cm)

1/2(31.42cm)

15.71cm

Answer:

15.71 cm

Step-by-step explanation:

remember the formula for the circumference of a circle but make it half since it's a semi-circle

the perimeter of a circle is diameter x pi

since

the diameter is 10 and pi is 3.142

its 10 x 3.142

and that equals

31.42

that's a FULL circle so half of that

divide it by 2

31.42/2=15.71

so the diamater of the semi-circle is 15.71

hope this helps!

dont forget is centimeters

Sandy made an origami dog. What is the area of the parallelogram highlighted in the origami​ figure?

Answers

Answer:

the area = base × height = 2 × 3.32 = 6.64 ft²

Answer:

incorrect answer

Step-by-step explanation:

Solve 7+7a=7(2-b) for b

Answers

Answer:

b = 1 - a

Step-by-step explanation:

Given

7 + 7a = 7(2 - b) ← divide both sides by 7

1 + a = 2 - b ( subtract 2 from both sides )

- 1 + a = - b ( multiply through by - 1 )

1 - a = b

Answer:

[tex]b = (a - 1)[/tex]

Step-by-step explanation:

Question

[tex]7 + 7a = 7(2 - b)[/tex]

First Solve the brackets

[tex]7 + 7a = 7(2 - b) \\ 7 + 7a = 14 - 7b[/tex]

Then Make the b as the Subject

[tex]7 + 7a = 14 - 7b \\7 + 7a - 14 = 7b \\ 7a - 7 = 7b \\ 7(a - 1) = 7b \\ \frac{7(a - 1)}{7} = \frac{7b}{7} \\ a - 1 = b[/tex]

hope this helps you.

Have a nice day!

ABC is a triangle. AC = 9 cm, BC = 7 cm and angle BAC = 30°
Calculate the size of angle ABC.

Answers

9514 1404 393

Answer:

  ∠B = 40°  or  140°

Step-by-step explanation:

The given angle is opposite the shortest of the given sides, so there are two possible solutions.

From the law of sines, ...

  B = arcsin(b/a·sin(A)) = arcsin(9/7·sin(30°)) = arcsin(9/14)

Possible values for angle B are ...

  B = arcsin(9/14) ≈ 40.0°

  B = 180° -arcsin(9/14) ≈ 140.0°

How would you find out how many sixth through eighth grade students are interested in joining a running club?

Answers

The question is incomplete. The complete question is :

How would you find out how many sixth through eighth grade students are interested in joining a running club? Explain how to choose a sample that will give you a good representation of a whole population.

Answer :

the sample should be random

Explanation :

We have to find the number of student from 6th through 8th grade students those who wanted to join a running club by choosing a sample of population. So in order to choose a sample which will provide a good representation for the whole population is that the sample must be a [tex]\text{random sample}[/tex] from  [tex]\text{entire set of students }[/tex] and it should also include enough students to be reliable. The smaller samples have a more variation that lead to a lesser reliable inference.

Cam can't figure out what to eat. He is going to randomly select a piece of fruit from his pantry. There are 444 apples and 555 bananas in his pantry.
What is \text{P(select an apple})P(select an apple)start text, P, left parenthesis, s, e, l, e, c, t, space, a, n, space, a, p, p, l, e, end text, right parenthesis?
If necessary, round your answer to 222 decimal places.

Answers

Answer:

0.45

Step-by-step explanation:

no. of outcomes = 4+5 = 9

favourable outcomes = 4

P(an apple) = 4/9

= 0.4444... or 0.45

Mustafa is flying his kite, and Ana is watching from 20 m away, as shown. From Ana's perspective there is an
angle of 109 between Mustafa and his kite. The length of the string between Mustafa and the kite is 46 m.
Kite
46 m
109
?
Mustafa
Ana
20 m
From Mustafa's perspective, what is the angle between Ana and the kite?
Do not round during your calculations. Round your final answer to the nearest degree.

Answers

7.80 because it’s is a number everyone know

Answer: From Mustafa's perspective, there is a 47\degree47°47, degree angle between Ana and the kite.

Step-by-step explanation: Khan Academy

The point (1,−1) satisfies the inequality 40x−22y≤50.

Answers

Không thảo mãn vì

44.1-22.(-1)=66

No, the point (1,-1) does not the satisfy the inequality 40x-22y<=50.

What is an inequality?

It is a type of equation in which greater than less than or equal to are used instead of only equal to.

How to solve an inequality?

To check whether whether a point satisfies an inequality or not we need to just put it in the inequality. So,

40x-22y<=50

40(1)-22(-1)=40+22=62

62 is not less than and not equal to 50. So it does not satisfies the inequality.

Learn more about inequality at https://brainly.com/question/24372553

#SPJ2

Solve x2 + 10x + 7 = 0 by completing the square.

Which equation is used in the process?

( x + 5) 2 = 32
( x + 5) 2 = 18
( x + 10) 2 = 93

Answers

The answer is second
(x+5)2 = 18

‼️‼️HELP HELP ILL MARK YOU BRAINLEST ‼️‼️

your parents took your family out to dinner. your parents wanted to give the waiter a 15% tip. if the total amount of the dinner was $82.00 what should be paid to the waiter as a tip?

a)$12.30

b)$8.00

c)12.03

d)$13.00​

Answers

Answer:

A = $12.30

Step-by-step explanation:

15 × 82 = 12.3

100

It takes a train 8 hours to travel a distance of 216 km. What is the average speed of the train?

Answers

(S=D/T)S=216KM, T=8HOURS : 216/8=27KM/HOUR

The average speed of the train is 27 km/hour if It takes a train 8 hours to travel a distance of 216 km.

What is the distance?

Distance is a numerical representation of the distance between two items or locations. Distance refers to a physical length or an approximation based on other physics or common usage considerations.

We have:

It takes a train 8 hours to travel a distance of 216 km.

As we know,

Average speed = distance/time

Average speed = 216/8 = 27 km/hour

Thus, the average speed of the train is 27 km/hour if It takes a train 8 hours to travel a distance of 216 km.

Learn more about the distance here:

brainly.com/question/26711747

#SPJ2

Which Greek mathematician wrote the most definitive text on geometry, one that is still referred to today?
A.
Thales
B.
Pythagoras
C.
Euclid
D.
Archimedes
E.
Hippocrates

Answers

it’s d




because once d lives someone’s dogs lives

What is the circumference of the circle in terms of pi 30 in?

Answers

Step-by-step explanation:

Given radius = 30 in.

Circumference is given by 2πr

= 2 × π × 30

= 60π in

The given radius is 30 inches

a) vẽ đồ thị hàm số y=2x-3(d1)

b) tìm toạ độ giao điểm B của (d1) với (P):y=x^2

c)tìm m để đường thẳng (d2):y=(m-1)x-m-3 đi qua B

Answers

Answer:

Step-by-step explanation:

Find the area of the equilateral triangle below. Round to 1 point
the nearest tenth.

Answers

Answer:

25√3mm

Step-by-step explanation:

this might be the answer..

Answer:

[tex]25\sqrt{3}[/tex]

Step-by-step explanation:

[tex]\frac{10^2*\sqrt{3} }{4}[/tex]

-78 + (-30)=
HINT = - + = -​

Answers

Answer:

-108 is the answer to the question..

Answer:

​-108

Step-by-step explanation:

Solve for x. Leave your answer in simplest radical form.

Answers

There are two Right angled triangles in the given figure, with two missing sides, let's name the other missing side be " y "

According to Pythagoras theorem,

[tex] \boxed{ \large \boxed{h {}^{2} = {b}^{2} + p{}^{2} }}[/tex]

note :

p = perpendicular / opposite sideb = base / adjacent sideh = hypotenuse

let's solve for " y² " first ( square of other missing side )

[tex]➢ \: \: {y}^{2} = {8}^{2} + 3 {}^{2} [/tex]

[tex]➢ \: \: {y}^{2} = 64 + 9[/tex]

[tex]➢ \: \: {y}^{2} = 73[/tex]

now let's solve for " x " , by using pythagorous theorem

[tex]➢ \: \: {x}^{2} = {y}^{2} + {6}^{2} [/tex]

[tex]➢ \: \: {x}^{2} = 73 + 36[/tex]

[tex]➢ \: \:x {}^{2} = 109[/tex]

[tex]➢ \: \: x = \sqrt{109} [/tex]

Approximate :

[tex]➢ \: \: 10.44 \: \: units[/tex]

[tex] \mathrm{✌TeeNForeveR✌}[/tex]

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