b: \(\Leftrightarrow15x^2+3x+10x+2=15x^2+21x-5x-7\)
=>13x+2=16x-7
=>-3x=-9
hay x=3
c: =>x(x+1)=0
=>x=0 hoặc x=-1
\(\left(b\right):\dfrac{3x+2}{5x+7}=\dfrac{3x-1}{5x+1}\left(ĐK:x\ne\left\{-\dfrac{7}{5};-\dfrac{1}{5}\right\}\right)\\ =>\left(3x+2\right)\left(5x+1\right)=\left(3x-1\right)\left(5x+7\right)\\ =>15x^2+10x+3x+2=15x^2-5x+21x-7\\ =>15x^2+13x+2=15x^2+16x-7\)
\(=>15x^2-15x^2+16x-13x=7+2\\ =>3x=9\\ =>x=3\)
\(\left(e\right):x^2+x=0\\ =>x\left(x+1\right)=0\\ =>\left[{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
