a: \(\Leftrightarrow x^2+2x+1-x^2+2x-1=4\)
=>4x=4
hay x=1(loại)
b: \(\Leftrightarrow6\left(x-8\right)+2\left(x-5\right)=-18-\left(x-8\right)\left(x-5\right)\)
\(\Leftrightarrow6x-48+2x-10+18+x^2-13x+40=0\)
\(\Leftrightarrow x^2-5x=0\)
=>x(x-5)=0
=>x=0(nhận) hoặc x=5(loại)
c: \(\Leftrightarrow3\left(x-2\right)-x-1=9\)
=>3x-6-x-1=9
=>2x-7=9
=>2x=16
hay x=8(nhận)


