2x-5y= -50
Multiply by 5 to get rid of the fraction and you're left with 5y-30=2(x+10)
Distribute the 2 to get 5y-30=2x+20
Add 30 to both sides and you get 5y=2x +50
Subtract 5y from both sides to move it to the other side: 0=2x-5y+50
Subtract 50 from both sides: 2x-5y = -50