Sally used a ruler to draw the segment ab she then opened her compass to the length of ab and drew a circle keeping thw compass open to the same length she marked off equal parts along the circle as shown in the following figure using some or all of the points of intersection and point a which of the following regular polygons could she construct

Answer:

(cotA − 1) (cotB − 1) = 2

Step-by-step explanation:

A+B= π/4 = 180°/4 = 45°

A+B=45°

∴ cot(A+B)=cot45°

∴ cotBcotA−1 / (cotB+cotA) = 1

⇒cotB + cotA = cotBcotA = 1

⇒cotB + cotA − cotBcotA + 1 = 0

⇒cotBcotA − cotB − cotA − 1 = 0

⇒cotBcotA − cotB − cotA − 1 + 2 = 0+2

⇒cotBcotA − cotB − cotA + 1 = 2

⇒cotB(cotA − 1) (cotA − 1) = 2

⇒(cotA − 1) (cotB − 1) = 2

Proved

Answer:

x=20

Step-by-step explanation:

The solution to the system of equations expressed as a coordinate point is [tex](x.y)=(-1,1)[/tex]

To solve the system

[tex]3x + y = -2\\y = 2x + 3[/tex]

Note that [tex]y[/tex] is already made subject of formula in [tex]y = 2x + 3[/tex]. So substitute the value for [tex]y[/tex] into [tex]3x + y = -2[/tex] to eliminate [tex]y[/tex] and leave us with an equation with [tex]x[/tex]

[tex]3x + y = -2\\3x + (2x+3) = -2\\3x+2x+3=-2\\3x+2x=-2-3\\5x=-5\\\frac{5x}{5}=\frac{-5}{5}\\x=-1[/tex]

Substitute this value of [tex]x[/tex] into [tex]y = 2x + 3[/tex] to get the value of [tex]y[/tex]

[tex]y = 2(-1) + 3\\y=-2+3\\y=1[/tex]

The solutions are [tex]x=-1,y=1[/tex], or expressed as a coordinate point

[tex](x.y)=(-1,1)[/tex]

Learn more about systems of equations here: https://brainly.com/question/16763389

666666666666666666766666666

Answer:

c

Step-by-step explanation:

i saw the answer sheet :)

Answer: The answer is 8.91.

Answer : 8.91

Step - by - step explanation :

Sometimes if a question is to big for you - it's best to start off small . . .

4.60 + 3.28 = 7.88

7.88 + 1.03 = 8.91

The area of the pennant made by Clara is 90 in²

Area is the amount of space taken up by a two dimensional figure. It measures the quantity of space covered by the figure.

Area of the rectangle = length * width = 6 in * 1 in = 6 in²

Area of triangle = (1/2) * base * height = (1/2) * 6 in * 28 in = 84 in²

Area of the pennant = 6 in² + 84 in² = 90 in²

The area of the pennant made by Clara is 90 in²

Find out more on Area at: https://brainly.com/question/25292087

Answer:

90in^2

Step-by-step explanation:

Area of the rectangle = length times width = 6 x1 = 6 in^2

then the Area of triangle = 1/2 base times height = (1/2) x 6 x 28= 84 in^2

and the Area of the pennant is = 6 + 84 = 90 in

Step-by-step explanation:

The sample sizes are quite large, so the central limit theorem applies. (It typically does as soon as the sample size exceeds 30 or so.) This means that the sample mean will be approximately normally distributed with the same mean 22 but standard deviation 3.1/√40 ≈ 0.4902.

Now, if the question is asking about the probability of the sample mean being an exact number, that probability would be zero.

But if you meant to ask something else, like "what is the probability that the sample mean is less than 21?" then we would have a non-zero probability. In this particular case, if Y is a random variable for the sample mean, then

Pr[Y < 21] = Pr[(Y - 22)/(3.1/√40) < (21 - 22)/(3.1/√40)]

… ≈ Pr[Z < -2.0402]

… ≈ 0.0207

Answer:

x = 20°

Step-by-step explanation:

OA = OB

so 140°+x°+x° = 180°

140+2x = 180

2x = 40

x = 20°

Answer:

Its D. 36

Step-by-step explanation:

Answer:

round to cent 20.59

Step-by-step explanation:

Answer: $238

Step-by-step explanation:

120/6 = 20 shirts for $7

680 / 20 = 34 lots of shirts costing $7

the cost = 34 x 7 = $238

Answer:

238$

Step-by-step explanation:

680*6=4080

this is how many buttons used

4080/120=34

this is how many boxes of buttons

34*7=238

this is the amount

Answer:

x=  47 18+2  201  i  ≈0.382978723+0.603295612i x=  47 −2  201  i+18  ≈0.382978723−0.603295612i  Hopefully this makes just the same amount of sense as this question

Answer:

Step-by-step explanation:

Use law of cosines

c² = a² + b² - 2abcosθ

cosθ = (c² - a² - b²) / -2ab

c = length of AC = √(8 - 5)² + (4 - (-5))² = √90

b = length of AB = √(8 - 6)² + (4 - 3)² = √5

a = length of BC = √(6 - 5)² + (3 - (-5))² = √65

cosθ = (√90² - √65² - √5²) / -2√65√5

cosθ = 20 / -36.05551...

cosθ = - 0.5547001

θ = 123.69°

Using the z-distribution, it is found that the p-value is of 0.5975.

At the null hypothesis, it is tested if the proportions are equal, that is, their subtraction is 0, hence:

[tex]H_0: p_1 - p_2 = 0[/tex]

At the alternative hypothesis, it is tested if they are different, that is, their subtraction is not 0, hence:

[tex]H_1: p_1 - p_2 \neq 0[/tex]

The sample sizes and proportions are given by:

[tex]n_1 = 631, p_1 = \frac{133}{631} = 0.2108[/tex]

[tex]n_2 = 121, p_2 = \frac{23}{121} = 0.1901[/tex]

The standard errors are given by:

[tex]s_1 = \sqrt{\frac{0.2108(0.7892)}{631}} = 0.0162[/tex]

[tex]s_2 = \sqrt{\frac{0.1908(0.8092)}{121}} = 0.0357[/tex]

For the distribution of differences, the estimate and the standard error are:

[tex]\overline{p} = p_1 - p_2 = 0.2108 - 0.1901 = 0.0207[/tex]

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.0162^2 + 0.0357^2} = 0.0392[/tex]

The test statistic is given by:

[tex]z = \frac{\overline{p} - p}{s}[/tex]

In which [tex]p = 0[/tex] is the value tested at the null hypothesis.

Then:

[tex]z = \frac{\overline{p} - p}{s}[/tex]

[tex]z = \frac{0.0207 - 0}{0.0392}[/tex]

[tex]z = 0.528[/tex]

Using a z-distribution calculator, with a two-tailed test, as we are testing if the mean is different of a value, the p-value is of 0.5975.

A similar problem is given at https://brainly.com/question/25869410

Answer:

Some solutions of 9x−2y=18 are x=5 =−18 ; x=7 and y=19 ; x=9 and y=0 ; x=11 and y=9 and x=13 and y=18 .

Step-by-step explanation:

The decrease is  (95-68) = 27 .

As a fraction, the decrease is  27/95  of the original amount.

To change any fraction to a decimal, do the division:

                            (27)  divided by  (95) = 0.2842...

To change any decimal to a percentage, move the

decimal point two places that ==> way:

                            0.2842...  =  28.42... %Answer:

Step-by-step explanation:

[tex]\qquad[/tex]☀️ At first we need to find out the difference between 95 and 68.

[tex]\qquad[/tex][tex] \sf \longrightarrow 68 -95 \\[/tex]

[tex]\qquad[/tex][tex] \sf \longrightarrow -27[/tex]

[tex]\qquad[/tex]☀️ Now, divide the number by "the starting number.

[tex]\qquad[/tex][tex] \sf \longrightarrow \dfrac{-27 }{97}[/tex]

[tex]\qquad[/tex][tex] \sf \longrightarrow -0.2842[/tex]

[tex]\qquad[/tex]☀️ And finally, we have to multiply the result by 100 to get it in terms of percent.

[tex]\qquad[/tex][tex] \sf \longrightarrow -0.2842 \times 100[/tex]

[tex]\qquad[/tex][tex] \red{\bf \longrightarrow -28.42℅}[/tex]

[tex]\qquad[/tex]_________________________

Answer:

The gradient is negative.

Step-by-step explanation:

The gradient represents the rise/run ratio. Always read the line's path left to right, and if it goes up, then it is positive, down means negative gradient, and if it doesnt move then it 0. It is undefined if the line is vertical.

Answer:

Step-by-step explanation:

if x is the number of times you go swimming

100 + 4x < 6x

Out of an 98 day season

If you attend 50 days, the cost is $300 either with or without the membership

Less than 50 days, it's less expensive to just pay the daily rate.

More than 50 days, it's less expensive to have the membership.

Answer:

4900

Step-by-step explanation:

70^2 means 70*70

70*70=4900

Answer:

you will do 70 times 70 because 70^2 is 70 times 70 which is 4,900.

x = 27

Step-by-step explanation:

The two angles shown are called co-exterior angles and by definition, their sum is equal to 180° so we can write

[tex](3x - 3) + (4x - 6) = 180[/tex]

[tex]\Rightarrow 7x - 9 = 180[/tex]

Simplifying this further, we get

[tex]7x = 189 \Rightarrow x = 27[/tex]

Answer:

(40*4)-(32*4)=32

160-128=32

Step-by-step explanation:

Answer:

[tex]x=-1,1,-\sqrt{\frac{7}{4} },\sqrt{\frac{7}{4}}[/tex] and [tex]y=-1,\frac{1}{2}[/tex]

The ordered pair solutions are [tex](-\sqrt{\frac{7}{4}},0.5)[/tex], [tex](\sqrt{\frac{7}{4}},0.5)[/tex], [tex](-1,-1)[/tex], and [tex](1,-1)[/tex].

Step-by-step explanation:

I'm assuming the system is [tex]\left \{ {x^2+y^2=2} \atop {y=2x^2-3}} \right.[/tex]:

[tex]x^2+y^2=2[/tex]

[tex]x^2+(2x^2-3)^2=2[/tex]

[tex]x^2+(4x^4-12x^2+9)=2[/tex]

[tex]x^2+4x^4-12x^2+9=2[/tex]

[tex]4x^4-11x^2+9=2[/tex]

[tex]4x^4-11x^2+7=0[/tex]

[tex]x^4-11x^2+28=0[/tex]

[tex](x^2-7)(x^2-4)=0[/tex]

[tex](4x^2-7)(x^2-1)=0[/tex]

[tex]4x^2-7=0[/tex]

[tex]4x^2=7[/tex]

[tex]x^2=\frac{7}{4}[/tex]

[tex]x=\pm\sqrt{\frac{7}{4}}[/tex]

[tex]x^2-1=0[/tex]

[tex]x^2=1[/tex]

[tex]x=\pm1[/tex]

[tex]y=2x^2-3[/tex]

[tex]y=2(\pm\sqrt{\frac{7}{4}})^2-3[/tex]

[tex]y=2({\frac{7}{4}})-3[/tex]

[tex]y=\frac{7}{2}-3[/tex]

[tex]y=\frac{1}{2}[/tex]

[tex]y=2x^2-3[/tex]

[tex]y=2(\pm1)^2-3[/tex]

[tex]y=2(1)-3[/tex]

[tex]y=2-3[/tex]

[tex]y=-1[/tex]

Therefore, [tex]x=-1,1,-\sqrt{\frac{7}{4} },\sqrt{\frac{7}{4}}[/tex] and [tex]y=-1,\frac{1}{2}[/tex]

The ordered pair solutions are [tex](-\sqrt{\frac{7}{4}},0.5)[/tex], [tex](\sqrt{\frac{7}{4}},0.5)[/tex], [tex](-1,-1)[/tex], and [tex](1,-1)[/tex].

Answer:

[tex] \frac{1}{4} [/tex]

[tex] \frac{1}{3} [/tex]

Answer:

16feet

part B is 18 feed for a good at a better than the price but the one

Answer:

7.44miles

Step-by-step explanation:

1km = 0.62miles

12km will be ; 0.62 × 12

= 7.44miles

Answer:

Cost of 1 pound apple:4.80/6=2.4

cost of 9 pounds apple:2.4 ×9=21.6

Correct me if im wrong po

Answer:

B)

Step-by-step explanation:

2(n+7)+3n

now you multiply 2 though

2n+14+3n

Add common factors

5n+14

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Hope this helps!!

If I am wrong, please tell me, I enjoy learning from my mistakes:)