Question

Tìm x

(2x-1)³-4x².(2x-3)=5

Answer 1

Ta có : \(\left(2x-1\right)^3-4x^2\left(2x-3\right)=5\)

\(\Rightarrow\left(8x^3-12x^2+6x-1\right)-\left(8x^3-12x^2\right)=5\)

\(\Rightarrow6x-1=5\)

\(\Rightarrow6x=6\Rightarrow x=1\)

Vậy x = 1

Answer 2

x=1

Answer 3

\(\left(2x-1\right)^3-4x^2\left(2x-3\right)=5\Leftrightarrow\left(8x^3-12x^2+6x-1\right)-\left(8x^3-2x^2\right)=5\)\(\Leftrightarrow8x^3-12x^2+6x-1-8x^3+12x^2-5=0\)\(6x-6=0\Leftrightarrow6\left(x-1\right)=0\Rightarrow x-1=0\Rightarrow x=1\)