Đáp án+Giải thích các bước giải:
$a) 6x(5x+3)+3x(1-10x)=7$
$⇔30x²+18x+3x-30x²=7$
$⇔21x=7$
$⇔x=1/3$
$c) (x+1)(x+2)(x+5)-x²(x+8)=27$
$⇔(x²+2x+x+2)(x+5)-x²-8x²=27$
$⇔x³+5x²+2x²+10x+x²+5x+2x+10-x²-8x²=27$
$⇔17x-17=0$
$⇔17x=17$
$⇔x=1$
$d) (-2x+3)(x²+11)+x²(2x+13)=0$
$⇔-2x³-22x+3x²+33+2x³+13x²=0$
$⇔16x²−22x+33=0$
$⇔16x²-22x=-33$
$⇔-6x³=-33$
$⇔x=11/2$
Chúc bn hc tốt🥰
$\text{#LinhSad}$