Question

Giải các pt sau :

(x-2)(x+2)-(2x+1)² =x(2-3x)

#tick_3_bạn_nhanh_nhất

Answer 1

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

\(\Leftrightarrow x^2-4-4x^2-4x-1=2x-3x^2\)

\(\Leftrightarrow-3x^2+3x^2-4x-2x=1+4\)

\(\Leftrightarrow-6x=5\Leftrightarrow x=-\dfrac{5}{6}\)

Vậy......

Answer 2

(x-2)(x+2)-(2x+1)2 =x(2-3x)

\(\Leftrightarrow x^2-4-4x^2-4x-1=2x-3x^2\)

\(\Leftrightarrow x^2-4-4x^2-4x-1-2x+3x^2=0\)

\(\Leftrightarrow-6x-5=0\)

\(\Leftrightarrow x=\dfrac{-5}{6}\)

\(\Rightarrow S=\left\{\dfrac{-5}{6}\right\}\)

Answer 3

<=> \(x^2-4-4x^2-4x-1=2x-3x^2\)

<=> \(x^2-4x^2+3x^2-4x-2x=4+1\)

<=> \(-6x=5\)

<=> \(x=-\dfrac{5}{6}\)

Answer 4

(x-2)(x+2)-(2x+1)²=x(2-3x)

\(x^2-4-4x^2-4x-1=2x-3x^2\)

\(x^2-4-4x^2-4x-1-2x+3x^2=20\)

\(-6x-5=0\)

\(x=\dfrac{-5}{6}\)