Hi there!

To solve this problem using substitution, we need to set x equal to a value and substitute it into the other equation.

Since
x - 4y = 5,
x = 5 + 4y

3x - 7y = 10
3(5 + 4y) - 7y = 10
15 + 12y - 7y = 10
15 + 5y = 10
5y = -5
y = -1

Now that we know y is -1, we can substitute it back into the equation to find x:

y = -1
x - 4y = 5
x - 4(-1) = 5
x - (-4) = 5
x + 4 = 5
x = 1

So, your answers are x = 1 and y = -1.

Hope this helps!

6 0

3 years ago

55% of 19.6 is what number?

tiny-mole [99]

10.78 is the answer.
19.6 x .55

3 0

3 years ago

Ok now these are my very last points please help

Snowcat [4.5K]

Answer:

wait what grade are you in ?

5 0

3 years ago

The owners of an eyeglass store claim that they fill customers' orders, on average, in 60 minutes with a standard deviation of 1

melomori [17]

By applying z-score formula we got that if a reporter determines a mean order time of 63 minutes then value o Z is 1.19

<h3>What is standard deviation?</h3>

Standard deviation is a number used to tell how measurements for a group are spread out from the average (mean), or expected value

Here given that

The owners of an eyeglass store claim that they fill customers' orders, on average, in 60 minutes with a standard deviation of 15. 9 minutes. Based on a random sample of 40 orders, a reporter determines a mean order time of 63 minutes

mean=μ=60

standard deviation=σ=15.9

number of sample=n=40

$\bar{x}=63 \\$

Now we can calculate z by z-score formula as

$z=\frac{\bar{x}-\mu}{\frac{\sigma}{\sqrt{n}}} \\\\&=\frac{63-60}{\frac{15 \cdot 9}{40}} \\ \\=\frac{3}{2.5140} \\ \\=1.19\end{aligned}$

By applying z-score formula we got that if a reporter determines a mean order time of 63 minutes then value o Z is 1.19

To learn more about standard deviation visit :brainly.com/question/12402189

5 0

2 years ago