Question

Tìm x : (x-2)(x+4)-4x(x-3)=-8+3x

Answer 1

`(x-2)(x+4)-4x(x-3)=-8+3x`

`<=>x^2+2x-8-4x^2+12x-3x+8=0`

`<=>11x-3x^2=0`

`<=>x(11-3x)=0`

`th1:x=0`

`th2:11-3x=0`

`<=>11=3x`

`<=>x=11/3`

Vậy `S={0,11/3}`

Answer 2

\(\left(x-2\right)\left(x+4\right)-4x\left(x-3\right)=-8+3x\)

\(< =>x^2+4x-2x-8-4x^2+12x+8-3x=0\)

\(< =>-3x^2+11x=0\)

\(< =>-3x\left(x-\dfrac{11}{3}\right)=0=>x=\dfrac{11}{3}\)