Ok here it is:
4x-5y=40
2x+10y=20
I used the second equation and decided to get x
2x+10y=20
Subtract 10y from both sides.
2x=-10y+20
Divide both sides by 2
x=-5y+10
Put that in for x for first equation
4(-5y+10)-5y=40
Distribute the 4
-20y+40 -5y =40
Combine like terms
-25y+40=40
Subtract 40 from both sides
-25y=0
Divide by -25 on both sides
y=0
Substitute the y in for the 2nd equation
2x+10(0)=20
2x=20
Divide both sides by 2
x=10
So x=10 and y=0
