667. 5-100х-90=-3
-100х =-3-5+90
-100х =82
х = - 0,82
668. -7+14х-4=10
14х = 10+7+4
14х = 21
х = 1,5
669. -7 -10х +12 = -2
-10х = -2-12+7
-10х =-7
х = 0.7
670. -4х = -9-2+2
4х = 9
х =2,25
671. 10+2х+14 =9
2х = 9 -10-14
2х = -15
х = -7,5
672. 8+28х-32=4
28х = 4+32-8
28х =28
х = 1
673. 1-12х+18=-2
- 12х = -2 -18 -1
-12х =-21
х=1,75
674. 10-90-81х=8-х
-81х+х =8+90-10
-80х =88
х = -1,1
675. -1+56-48х =2х+6
-48х-2х = -56+6+1
-50х = -49
х=0,98
676. -2+3+6х =-2х+3
6х+2х=3-3+2
8х =2
х=0,25
677. -3х+4 = -10-35-5х
-3х +5х = -10-35-4
2х = -49
х= -24,5