Question

\(\text{x^2 -2x = 24 }\)

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

tìm x help me :)))

Answer 1

\(x^2-2x=24\\ x^2-2x-24=0\\ x^2+4x-6x-24=0\\ x\left(x+4\right)-6\left(x+4\right)=0\\ \left(x-6\right)\left(x+4\right)=0\\ \Rightarrow\left\{{}\begin{matrix}x-6=0\\x+4=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)

vậy x = {6; -4}

Answer 2

mị ko bt đây là toán 8

Answer 3

\(\left(x+2\right)^2-9=0\\ \left(x+2\right)^2=9\\ \left(x+2\right)^2=3^2\\ \left\{{}\begin{matrix}x+2=3\\x+2=-3\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=1\\x=-5\end{matrix}\right.\)

vậy x = {1; -5}