A=1 b=3 c=2
D=9-8=1
x1=-3+1/2=-1
x2=-3-1/2=-1
Ответ: -2 и -1
( -3,25 -2,75) : (-0,6) + 0,8 * (-7) =
=(-6):(-0.6) - 5.6 =
= 10-5.6 = 4.4
680.
6х+56-72х=-2х-8
6х-72х+2х=-8-56
-64х=-64
х=-64÷(-64)
х=1
$$$$$$$
681.
3х-2-3х-15=-2+х-5
-17=-7+х
х=-17+7
х=-10
$$$$$$$$
682.
х-1+х+2=20+4х-5
2х+1=15+4х
2х-4х=15-1
-2х=14
х=-7
$$$$$$$$
683.
-2х+1-3х+12=12-4х+4
-5х+13=16-4х
-5х+4х=16-13
-х=3
х=-3
2х-(32х+24)=0; 2х-32х-24=0; -30х-24=0