№80.
1) 3х = -6
х = (-6):3
х = -2
2) х+3 = 6
х = 6-3
х = 3
3) 4х-4 = х+5
4х-х = 5+4
3х = 9
х = 9:3
х = 3
4) 5х-8 = 2х+4
5х-2х = 4+8
3х = 12
х = 12:3
х = 4
№81.
1) х+5 = -6
х = - 6-5
х = -11
2) 4-х = -1
-х = -1-4
-х = -5
х = 5
3) 2х - 1 = 0
2х = 0+1
2х = 1
х = 1:2
х = 0.5
4) 3х+2 = 0
3х = 0-2
3х = -2
х = (-2):3
х = -2/3
E)x=51/(-17)=-3
з)X=-13/2=-6,5
б)x-3=2
x=2+3=5
г)1/2x=4
x=4*2=8
е)2x-1/2=1
x=(3/2)/2=3/4
з)2-x=7
x=2-7=-5
б)5+x=3
x=3-5=-2
г)x-6=6
x=6+6=12
е)x+12=7
x=7-12=-5
з)x-3=-3
x=-3+3=0
к)-5x=100
x=100/(-5)=-20
x=11/5
x=2,2
м)-x=1
x=-1
(4c-d)*(6c+3d) 24c^2+12cd-6cd-3d^2 24c^2+6cd-3d^2
3^(log4_5)-5^(log4_3)=5^(log4_3)-5^(log4_3)=0
2,6х - 18,4 - 13 + 4,4х = 19,6
7х = 19,6 + 18,4 + 13
7х = 51
х = 51/7
х= 7 2/7