\(x^2+2x-x^2-3x=0\)
\(-x=0\)
\(x=0\)
\(x\left(x+2\right)=x\left(x+3\right)\\ \Leftrightarrow x\left(x+3\right)-x\left(x+2\right)=0\\ \Leftrightarrow x\left[\left(x+3\right)-\left(x+2\right)\right]=0\\ \Leftrightarrow x\left(x+3-x-2\right)=0\\ \Leftrightarrow x.1=0\\ \Leftrightarrow x=0\)
Vậy pt có tập nghiệm `S={0}`
x(x + 2) = x(x + 3)
<=> x2 + 2x = x2 + 3x
<=> x2 + 2x - x2 - 3x = 0
<=> -1x = 0
<=> x = 0