Question

[Trịnh Minh Châu]

\(\left(x-1\right)^3-x\left(x-1\right)^2=5x\left(2-x\right)-11\left(x+2\right)\)

MN GIÚP MK VS Ạ 

Answer 1

[☆MĭηɦღAηɦ❄]

\(\left(x-1\right)^3-x\left(x-1\right)^2=5x\left(2-x\right)-11\left(x+2\right)\)

\(< =>\left(x-1+x\right)\left(x-1\right)^2=10x-5x^2-11x-22\)

\(< =>-x^2+x-1-10x+5x^2+11x+22=0\)

\(< =>4x^2+3x+21=0\)

\(< =>\left(2x\right)^2+2.2x.\frac{3}{4}+\left(\frac{3}{4}\right)^2+20\frac{9}{25}=0\)

\(< =>\left(2x+\frac{3}{4}\right)^2+20\frac{9}{25}=0\)

Do \(\left(2x+\frac{3}{4}\right)^2\ge0=>\left(2x+\frac{3}{4}\right)^2+20\frac{9}{25}\ge20\frac{9}{25}>0\)

Vậy phương trình vô nghiệm

Answer 2

[☆MĭηɦღAηɦ❄]

Dòng 2 là (x-1-x) nha @@