Tìm x biết: x^2 - 7x = 0

1) x^2-7x=0
2)2x(x+3)+5(x+3)
3)x(x-4)+(x-4)(3x+1)=0
4)3x(2x-8)-(2x-8)^2=0
5)x(1-x)-(x-1)=0
6) (x-2)(x+3)+(x-2)(2x-1)=0
7)2x(x+1)=3(x+1)
8) (x+3)(2x+3)=(x+3)(x-4)
9)2(3-x)=x(-3+x)
10) (x-2)^2=(x-2)(2x+1)