a: \(\Leftrightarrow x^2+8x+16+4x^2-20x+25=5x^2+19\)
=>-12x+41=19
=>-12x=-28
hay x=7/3
b: \(\Rightarrow4x^2-20x+25-4x^2+24x-36=7x-12\)
=>7x-12=4x-11
=>3x=1
hay x=1/3
c: \(\Leftrightarrow\left(3x+10-2x+7\right)\left(3x+10+2x-7\right)=0\)
=>(x+17)(5x+3)=0
=>x=-17 hoặc x=-3/5