!SUBSTITUTION METHOD!

6y - 5z = -8
3z = -6
4x - 3y - 2z= 21

Step-by-step explanation:

6y - 5z = -8 Equation 1

3z = -6 Equation 2

4x - 3y - 2z= 21 Equation 3

First solve for z in Equation 2

That's

3z = - 6

Divide both sides by 3

Next substitute the value of z into Equation 1 in order to find y

We have

6y - 5(-2) = - 8

6y + 10 = - 8

6y = - 8 - 10

6y = - 18

Divide both sides by 6

Finally substitute the values of y and z into Equation 3 to find the value of x

That's

4x - 3(-3) - 2(-2) = 21

4x + 9 + 4 = 21

4x + 13 = 21

4x = 21 - 13

4x = 8

Divide both sides by 4

So the solutions are

Hope this helps you

answer: 819.89 miles across america

step-by-step explanation:

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)