b/ $2x(5-3x)+8x^{2}-3=2x^{2}+7$
<=> $2x(5-3x)+6x^{2}-10=0$
<=> $2x(5-3x)+2(3x-5)=0$
<=>$2x(5-3x)-2(5-3x)=0$
<=>$(5-3x)(2x-2)=0$
<=>$\left[ \begin{array}{l}5-3x=0\\2x-2=0\end{array} \right.$
<=>$\left[ \begin{array}{l}x=\frac{5}{3}\\x=1\end{array} \right.$
d/ $3x(2+4x)-5x^{2}-1=7x^{2}-7$
<=>$3x(2+4x)-12x^{2}+6=0$
<=>$6x+12x^{2}-12x^{2}+6=0$
<=>$6x+6=0$
<=>$x=-1$
Chúc em học tốt!
