Answer:
(15/2, -5/2)
Step-by-step explanation:
1. Sub x=5y+20 into 2x+2y=10 and simplify as shown below.
2(5y+20)+2y=10
10y+40+2y=10
12y+40=10
12y=-30
y=-30/12
y=-5/2
2. Sub in y=-5/2 into 2x+2y=10 to find x and simplify as shown below.
2x+2(-5/2)=10
2x-5=10
2x=15
x=15/2