Solve the equation 2x (x-1) - x (2x-5) = 9 fast kuai

Solve the equation 2x (x-1) - x (2x-5) = 9 fast kuai

2x(x-1)-x(2x-5)=9
2x^2-2x-2x^2+5x=9
3x=9
x=3