a: =>(x-2)(x+3)=0
=>x=2 hoặc x=-3
b: \(\Leftrightarrow x^2-2x+1-x^2+25=28\)
=>-2x=2
hay x=-1
c: \(\Leftrightarrow5x^2+6x-5x-6=0\)
=>(5x+6)(x-1)=0
=>x=-6/5 hoặc x=1
\(a,\Leftrightarrow\left(x-2\right)\left(x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\\ b,\Leftrightarrow x^2-2x+1+25-x^2=28\\ \Leftrightarrow-2x=2\Leftrightarrow x=-1\\ c,\Leftrightarrow5x^2-5x+6x-6=0\\ \Leftrightarrow\left(x-1\right)\left(5x+6\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{6}{5}\\x=1\end{matrix}\right.\)
a,⇔(x−2)(x+3)=0⇔[x=2x=−3b,⇔x2−2x+1+25−x2=28⇔−2x=2⇔x=−1c,⇔5x2−5x+6x−6=0⇔(x−1)(5x+6)=0⇔⎡⎣x=−65x=1