Need help with this one question

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natali 33 [55]

Q 9 the answer is 250

3 0

3 years ago

Which of the following equations is equivalent to x - y = 5?

Masja [62]

Answer:

$6x-6y=30$

Step-by-step explanation:

<u><em>The complete options are</em></u>

a) x - 2y = 30

b) 4x - 3y = 30

c) 3x - 4y = 30

d) 6x - 6y = 30

The given equation is

$x-y=5$

<u>Verify option d</u>

we have

$6x-6y=30$

Divide by 6 both sides

$(6x-6y)/6=30/6$

$\frac{6x}{6}-\frac{6y}{6}=\frac{30}{6}$

$x-y=5$

therefore

$x-y=5$ and $6x-6y=30$ are equivalent

3 0

4 years ago

A fifth grade teacher gives homework every night in both mathematics and language arts. The time to complete the mathematics hom

kherson [118]

Answer:

0.82% probability that the average time it takes to complete both homework assignments is greater than 82 minutes

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Math homework:

$\mu_M = 30, \sigma_M = 3$

Arts homework:

$\mu_A = 40, \sigma_A = 4$

What is the probability that the average time it takes to complete both homework assignments is greater than 82 minutes?

Here, we have a sum of normal variables. The mean will be the sum of the means, while the standard deviation is the square root of the sum of the variances. So

$\mu = \mu_M + \mu_A = 30 + 40 = 70$

$\sigma = \sqrt{\sigma_M^2 + \sigma_A^2} = \sqrt{3^2+4^2} = 5$

This probability is 1 subtracted by the pvalue of Z when X = 82. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{82 - 70}{5}$

$Z = 2.4$

$Z = 2.4$ has a pvalue of 0.9918

1 - 0.9918 = 0.0082

0.82% probability that the average time it takes to complete both homework assignments is greater than 82 minutes

3 0

3 years ago

The library charges 1$to use the copier and 0.50 for each page copied write an algebraic equation from situation

kicyunya [14]

Use C as the variable to find the cost of using the copier.
C=0.5x+1 since it costs .50 per page meaning the x is how many pages and 1 is the constant because it will always cost 1$ to use the copier.

5 0

3 years ago

Explain, in your own words, the steps necessary to solve a system of equations

DochEvi [55]

<h3>★ <u>Required Answer:-</u></h3>

<u>First, what is an equation?</u>

➳ A mathematical statement which shows that two algebraic expressions are equal is called and equation.

Or, LHS = RHS

<u>Example</u>:- 3x - 5 = x + 8

An equation is said to be a linear equation if it contains only one variable (literal) with highest power 1.

<u>Solving an equation:-</u>

To solve the equation x + 5 = 7 means to find the value of an unknown algebraic quantity used in the equation.

<u>Example</u>:-

To solve the equation x + 5 = 7 means to find the value of x.
To solve the equation 3y + 2 = 9 means to find the value of y.
To solve the equation $\sf \dfrac{2a}{3} + 4 = 10$ means to find the value of a ⠀⠀⠀⠀⠀⠀and so on!

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

★ <u>Rules for solving an equation by the substitution method:-</u>

Rule ❶

If x = 2, the value of the expression 3x + 2 = 3 × 2 + 2 = 6 + 2 = 8

Rule ❷

If x = 0, the value of the expression 3x + 2 = 3 × 0 + 2 = 0 + 2 = 2

Rule ❸

If x = -2, the value of the expression 3x + 2 = 3 × -2 + 2 = -6 + 2 = -4

Now consider the algebraic expression 5x - 2y

This expression consists of variables x and y.

Now if :-

x = 3 and y = 2, 5x - 2y = 5 × 3 2 × 2 = 15 - 4 = 11
x = 8 and y = 5, 5x - 2y = 5 × 8 - 2 × 5 = 40 - 10 = 30

⠀⠀⠀⠀⠀⠀⠀⠀

The process of finding the value of an algebraic expression by substituting the given value of its variable is called substitution.⠀⠀

5 0

3 years ago