Answer: 
Step-by-step explanation:
Given


is given by replacing the
by
from the 

Now,
is

First get y by its self , then graph , find intersection point and plug in x and y to both equations, see if it makes sense , then the solution must be you intersection point
1. Anwser=53.3 (do 40*3 then anwser x 4)
2anwser=120
1.77777777778 would be the answer you are looking for I think.
Answer:
x = 5.5 (Fraction 5 and one-half)
Step-by-step explanation:
18 - 7x = -20.5
-18 -18
-7x = -38.5
/-7 /-7
x = 5.5