Question

Answer 1

\(3x\left(x-5\right)-x^2+25=0\\ 3x\left(x-5\right)-\left(x^2-25\right)=0\\ 3x\left(x-5\right)-\left(x-5\right)\left(x+5\right)=0\\ \left(x-5\right)\left(3x-x-5\right)=0\\ \left(x-5\right)\left(2x-5\right)=0\\ \left[{}\begin{matrix}x-5=0\\2x-5=0\end{matrix}\right.\\ \left[{}\begin{matrix}x=5\\x=\dfrac{5}{2}\end{matrix}\right.\)

Answer 2

=>(x-5)(3x-x-5)=0

=>(2x-5)(x-5)=0

=>x=5 hoặc x=5/2