Giải thích các bước giải:
a.Ta có :
$2(7x+10)+5=3(2x-3)-9x$
$\to 14x+20+5=6x-9-9x$
$\to 14x+25=-3x-9$
$\to 14x+3x=-9-25$
$\to 17x=-34$
$\to x=-2$
b.Ta có :
$(x+1)(2x-3)=(2x-1)(x+5)$
$\to 2x^2-x-3=2x^2+9x-5$
$\to 10x=2$
$\to x=\dfrac15$
c.Ta có :
$\dfrac{x}{30}+\dfrac{5x-1}{10}=\dfrac{x-8}{15}-\dfrac{2x+3}{6}$
$\to x+3\left(5x-1\right)=2\left(x-8\right)-5\left(2x+3\right)$
$\to 16x-3=-8x-31$
$\to 24x=-28$
$\to x=-\dfrac76$
d.Ta có :
$\dfrac{x+4}{5}-x+4=\dfrac{x}{3}-\dfrac{x-2}{2}$
$\to 6\left(x+4\right)-30x+120=10x-15\left(x-2\right)$
$\to -24x+144=-5x+30$
$\to 19x=114$
$\to x=6$
