Answer:

Step-by-step explanation:
![\left[\begin{array}{ccc}x + 3y = 7\\x - 3y = 7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%20%2B%203y%20%3D%207%5C%5Cx%20-%203y%20%3D%207%5Cend%7Barray%7D%5Cright%5D)
Isolate
for
:
Substitute
:

Isolate
for
:
For

Substitute 



The solution to the system of equations are:

Hope I helped. If so, may I get brainliest and a thanks?
Thank you. Have a good day! =)
Answer:
The bottom question is wrong. You have to multiply 8 to get the amount earned. But the rest is correct.
Step-by-step explanation:
6.25 x 8 = 50
12.5 x 8 = 100
18.75 x 8 = 150
25 x 8 = 200
31.25 x 8 = 250
Answer:
x=1
Step-by-step explanation:
-4+7x=3 add 4 to both sides
7x=7 divide 7 on both sides
x=1
You have to subtract 4 from 7 and then add 5 and 3 then add 8 and 2 then multiply 10 with 3 to get 30.
Answer:
-3
Step-by-step explanation:
9-3(2)2
9-(6)2
9-12
-3