Question

cần giúp

Answer 1

\(a,\Leftrightarrow x^2+14x+49-x^2+3x=12\\ \Leftrightarrow17x=-37\Leftrightarrow x=-\dfrac{37}{17}\\ b,\Leftrightarrow x^2-2x-x+2=0\\ \Leftrightarrow\left(x-2\right)\left(x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=1\end{matrix}\right.\)

Answer 2

b: \(\Leftrightarrow\left(x-1\right)\left(x-2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=2\end{matrix}\right.\)