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3 years ago

PLEASE PLEASE PLEASE HELP! SOO STUCK!

Mathematics

1 answer:

coldgirl [10]3 years ago

4 0

Answer:80m^2

Step-by-step explanation:

Formula for trapezoid

1/2h(b1+b2)

1/2(8)(6+14)

4(20)=80

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The length of a swimming pool is 4 feet longer than 2 times its width. If the perimeter of the pool is 128 feet, what is the wid

alexandr1967 [171]

P = 2(L + W)
P = 128
L = 2W + 4

128 = 2(2W + 4 + W)
128 = 2(3W + 4)
128 = 6W + 8
128 - 8 = 6W
120 = 6W
120/6 = W
20 = W <=== width is 20 ft

L = 2W + 4
L = 2(20) + 4
L = 40 + 4
L = 44 <=== length is 44 ft

5 0

3 years ago

Tara and Edith share a sum of money in the ratio 13 : 12

svlad2 [7]

Answer:

She receives 108.33% ( or $108.33)

Step-by-step explanation:

Tara receives $108.33 because 13/12 into a percentage =108 times 100

which = 108.33.That's all there is to it! Hope you have a great day.

5 0

2 years ago

Can someone please help me I really need help please help me

Step2247 [10]

Answer:

Step-by-step explanation:

if it went down one more it would be 30

4 0

3 years ago

Write the following numbers in expanded notarion: a. 100 005. b. 84 016. c. 9 078. d. 113. e. 75.

shusha [124]

Answer:

Step-by-step explanation:

a. 100005

1 x 1000000 + 0 x 100,000 + 0 x 10000 + 0 x 1000 + 0 x 100 + 0 x 10 + 5 x1

1 x 10^6 + 0 x 10^5 + 0 x 10^4 + 0 x 10^3 + 0 x 10^2 + 0 x 10^1 + 5 x 1

= 100,000 + 0 + 0 +0 +0 + 5

b. 84016

8 x 10000 + 4 x 1000 + 0 x 100 + 1 x 10 + 6 x 1

80000 + 4000 + 0 + 10 + 6

c. 9078

9 x 1000 + 0 x 100 + 7 x 10 + 8 x 1

9000 + 0 +7 + 8

d. 113

1 x 100 + 1 x 10 + 3 x 1

100 + 10 + 3

e. 75

7 x 10 + 5 x 1

70 + 5

6 0

2 years ago

Match the identities to their values taking these conditions into consideration sinx=sqrt2 /2 cosy=-1/2 angle x is in the first

BaLLatris [955]

Answer:

$\cos(x+y)$ goes with $-\frac{\sqrt{6}+\sqrt{2}}{4}$

$\sin(x+y)$ goes with $\frac{\sqrt{6}-\sqrt{2}}{4}$

$\tan(x+y)$ goes with $\sqrt{3}-2$

Step-by-step explanation:

$\cos(x+y)$

$\cos(x)\cos(y)-\sin(x)\sin(y)$ by the addition identity for cosine.

We are given:

$\sin(x)=\frac{\sqrt{2}}{2}$ which if we look at the unit circle we should see

$\cos(x)=\frac{\sqrt{2}}{2}$ .

We are also given:

$\cos(y)=\frac{-1}{2}$ which if we look the unit circle we should see

$\sin(y)=\frac{\sqrt{3}}{2}$ .

Apply both of these given to:

$\cos(x+y)$

$\cos(x)\cos(y)-\sin(x)\sin(y)$ by the addition identity for cosine.

$\frac{\sqrt{2}}{2}\frac{-1}{2}-\frac{\sqrt{2}}{2}\frac{\sqrt{3}}{2}$

$\frac{-\sqrt{2}}{4}-\frac{\sqrt{6}}{4}$

$\frac{-\sqrt{2}-\sqrt{6}}{4}$

$-\frac{\sqrt{6}+\sqrt{2}}{4}$

Apply both of the givens to:

$\sin(x+y)$

$\sin(x)\cos(y)+\sin(y)\cos(x)$ by addition identity for sine.

$\frac{\sqrt{2}}{2}\frac{-1}{2}+\frac{\sqrt{3}}{2}\frac{\sqrt{2}}{2}$

$\frac{-\sqrt{2}+\sqrt{6}}{4}$

$\frac{\sqrt{6}-\sqrt{2}}{4}$

Now I'm going to apply what 2 things we got previously to:

$\tan(x+y)$

$\frac{\sin(x+y)}{\cos(x+y)}$ by quotient identity for tangent

$\frac{\sqrt{6}-\sqrt{2}}{-(\sqrt{6}+\sqrt{2})}$

$-\frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}+\sqrt{2}}$

Multiply top and bottom by bottom's conjugate.

When you multiply conjugates you just have to multiply first and last.

That is if you have something like (a-b)(a+b) then this is equal to a^2-b^2.

$-\frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}+\sqrt{2}} \cdot \frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}-\sqrt{2}}$

$-\frac{6-\sqrt{2}\sqrt{6}-\sqrt{2}\sqrt{6}+2}{6-2}$

$-\frac{8-2\sqrt{12}}{4}$

There is a perfect square in 12, 4.

$-\frac{8-2\sqrt{4}\sqrt{3}}{4}$

$-\frac{8-2(2)\sqrt{3}}{4}$

$-\frac{8-4\sqrt{3}}{4}$

Divide top and bottom by 4 to reduce fraction:

$-\frac{2-\sqrt{3}}{1}$

$-(2-\sqrt{3})$

Distribute:

$\sqrt{3}-2$

6 0

3 years ago