Bài 1:
1: \(=x^2\left(x+1\right)-4\left(x+1\right)=\left(x+1\right)\left(x-2\right)\left(x+2\right)\)
2: \(=x\left(x^3-8\right)=x\left(x-2\right)\left(x^2+2x+4\right)\)
3: \(=x^2-5x+3x-15=\left(x-5\right)\left(x+3\right)\)
Bài 3:
1: (x+3)(2x-5)=0
=>x+3=0 hoặc 2x-5=0
=>x=-3 hoặc x=5/2
2: =>(x-1)(2x-1)-x(1-x)=0
=>(x-1)(2x-1)+x(x-1)=0
=>(x-1)(3x-1)=0
=>x=1 hoặc x=1/3