Answer :
x^2(2y+5)=240
x^2(2(5)+5)=240
x^2+(10+5)=240
x^2+15=240
minus 15 both sides
x^2=225
sqrt both sides
x=15
x^2(2(5)+5)=240
x^2+(10+5)=240
x^2+15=240
minus 15 both sides
x^2=225
sqrt both sides
x=15