Question

1600/x-20-1600/x=4

Answer 1

1600/(x-20)-1600/x=4

1600x-1600(x-20)=4x(x-20)

1600x-1600x+32000=4x^2-80x

4x^2-80x-32000=0

x^2-20x-8000=0

(x-100)(x+80)=0

x1=100 x2=-80