630. -4х-4х=-5+3
-8х=-2
х=4
631. 4х-6х=-5-4
-3х=-1
х=3
632. 3х+7х=-2-3
10х=-5
х=-2
633. -8х+10х=1-3
2х=-2
х=-1
634.-6х+4х=-6-7
-2х=-13
х=6.5
635. -7х+8х=4+7
х=11
636. -4х+9х=-9-4
5х=-13
х=-2.6
637. -4х+8х=9-3
-12х=6
638. 2х-14=3
2х=3+14
2х=17
х=0.11
639. 5х-45=-2
5х=45-2
х=8.6
640. 3=4х+8
-4х=8-3
х= -0.8
641. -7=5х+25
-5х=25+7
х=6.4