Đáp án:
Giải thích các bước giải:
$a,x^3+x^2+x=x(x^2+x+1)$
$b,4x^2y-5x^3y-6xy^2=xy(4x-5x^2-6y)$
$c,15x^3y^3-5x^2y^3+20xy^2=5xy^2(3x^2y-xy+4)$
$d,8x^3(x-2)-x^2+2x$
$=8x^3(x-2)-x(x-2)$
$=(8x^3-x)(x-2)$
2.
$a,x^2-3x=0$
$(=)x(x-3)=0$
\(\left[ \begin{array}{l}x=0\\x-3=0\end{array} \right.\)
=>\(\left[ \begin{array}{l}x=0\\x=3\end{array} \right.\)
$b,2x(x-2)-(x-2)=0$
$(=)(2x-1)(x-2)=0$
\(\left[ \begin{array}{l}2x-1=0\\x-2=0\end{array} \right.\)
=>\(\left[ \begin{array}{l}x=\dfrac{1}{2}\\x=2\end{array} \right.\)
$c,(x-5)^2-x+5=0$
$(=)x^2-10x+25-x+5=0$
$(=)x^2-11x+30=0$
$(=)(x-6)(x-5)=0$
\(\left[ \begin{array}{l}x-6=0\\x-5=0\end{array} \right.\)
=>\(\left[ \begin{array}{l}x=6\\x=5\end{array} \right.\)
