Question

`g) 9(x – 3)^2 = 4(x + 2)^2`

Giải pt

Answer 1

\(\Leftrightarrow9x^2-54x+81=4x^2+16x+16\)

\(\Leftrightarrow5x^2-80x+65=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=8+\sqrt{51}\\x=8-\sqrt{51}\end{matrix}\right.\)

Answer 2

\(\Leftrightarrow\left(3x-9\right)^2-\left(2x+4\right)^2=0\)

\(\Leftrightarrow\left(3x-9-2x-4\right)\left(3x-9+2x+4\right)=0\)

\(\Leftrightarrow\left(x-13\right)\left(5x-5\right)=0\)

=>x=13 hoặc x=1