Question

Помогите))
21х-х2=0
18х2=162
3х2+2х-3=0

Answer 1

$21x-x^2=0$
$x(21-x)=0$
$x_1=0$
$21-x=0$
$x_2=21$

$18x^2=162$
$x^2=9$
$x=3$

$3x^2+2x-3=0$
$D=4+36=40$
$x_1=\frac{-2+\sqrt{40}}{6}=\frac{-1+\sqrt{10}}{3}$
$x_2=\frac{-2-\sqrt{40}}{6}=\frac{-1-\sqrt{10}}{3}$