3x-10y=-25Add 10y10y to both sides
3x=−25+10y
Regroup terms
3x=10y-253x=10y−25
Divide both sides by 3 3
x=10y-25/3
Factor out the common term 5 5
your answer: x=5(2y-5)/3
4x+40y=20
Factor out the common term 4 4
4(x+10y)=20
Divide both sides by 44
x+10y=20/4
Simplify 20/4 to 5
x+10y=5
Subtract 10y10y from both sides
your answer: x=5-10y