Determine the probability of choosing a pair need help

Madison saves 40% of all that she earns for washing cars. So far she has saved $72 . How much has she earned in all?

UkoKoshka [18]

Answer:

40% = 72

divide both sides by 40 to find 1%

1% = 1.8

now multiply by 100 to find total amount earned

100% = 180

total earned $180

7 0

3 years ago

In which of the expressions below will x = 3? Select all that apply.

Westkost [7]

Answer: b

Step-by-step explanation: 19 x 3 = 57 & 12 x 3= 36 so subtract 57 and 36 that’s going to give you 21 & 21 plus 6 is 27

7 0

3 years ago

A grocer takes a delivery of beverages from your truck at $6 per case. You unloaded 53 cases for the grocer today. How much does

Margarita [4]

Answer:

318$

Step-by-step explanation:

6*53 = 318$

3 0

3 years ago

Futhe Mathematics <img src="https://tex.z-dn.net/?f=%28Cos%20%7B%7D%5E%7B4%7Dt%20-Sin%20%7B%7D%5E%7B4%7Dt%20%29%20%20%5Cdiv%2

Nastasia [14]

Answer:

cos2t/cos²t

Step-by-step explanation:

Here the given trigonometric expression to us is ,

$\longrightarrow \dfrac{cos^4t - sin^4t }{cos^2t }$

We can write the numerator as ,

$\longrightarrow \dfrac{ (cos^2t)^2-(sin^2t)^2}{cos^2t }$

Recall the identity ,

$\longrightarrow (a-b)(a+b)=a^2-b^2$

Using this we have ,

$\longrightarrow \dfrac{(cos^2t + sin^2t)(cos^2t-sin^2t)}{cos^2t}$

Again , as we know that ,

$\longrightarrow sin^2\phi + cos^2\phi = 1$

Therefore we can rewrite it as ,

$\longrightarrow \dfrac{1(cos^2t - sin^2t)}{cos^2t}$

Again using the first identity mentioned above ,

$\longrightarrow \underline{\underline{\dfrac{(cost + sint )(cost - sint)}{cos^2t}}}$

Or else we can also write it using ,

$\longrightarrow cos2\phi = cos^2\phi - sin^2\phi$

Therefore ,

$\longrightarrow \underline{\underline{\dfrac{cos2t}{cos^2t}}}$

And we are done !

$\rule{200}{4}$

Additional info :-

Derivation of cos²x - sin²x = cos2x :-

We can rewrite cos 2x as ,

$\longrightarrow cos(x + x )$

As we know that ,

$\longrightarrow cos(y + z )= cosy.cosz - siny.sinz$

So that ,

$\longrightarrow cos(x+x) = cos(x).cos(x) - sin(x)sin(x)$

On simplifying,

$\longrightarrow cos(x+x) = cos^2x - sin^2x$

Hence,

$\longrightarrow\underline{\underline{cos (2x) = cos^2x - sin^2x }}$

$\rule{200}{4}$

7 0

2 years ago

What is the best description of the transformation shown?What is the best description of the transformation shown?

professor190 [17]

Answer:

The transformation is reflection

3 0

4 years ago

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