Question

(3x-2)²-(3x-1)(3x+4)=22

Answer 1

\(\left(3x-2\right)^2-\left(3x-1\right)\left(3x+4\right)=22\)

\(\Rightarrow9x^2-12x+4-9x^2-12x+3x+4=22\)

\(\Rightarrow-21x+8=22\)

\(\Rightarrow-21x=14\)

\(\Rightarrow x=-\dfrac{2}{3}\).

Vậy \(x=-\dfrac{2}{3}.\)

Answer 2

\(\left(3x-2\right)^2-\left(3x-1\right)\left(3x+4\right)=22\)

\(\Leftrightarrow9x^2-12x+4-\left(9x^2+12x-3x-4\right)=22\)

\(\Leftrightarrow9x^2-12x+4-9x^2-12x+3x+4-22=0\)

\(\Leftrightarrow-21x-14=0\Leftrightarrow-21x=14\Leftrightarrow x=\dfrac{-14}{21}=\dfrac{-2}{3}\) vậy \(x=\dfrac{-2}{3}\)