|9+x|-0,7=-0,7
|9+x| = 0
9+x = 0
x = -9
40 см к 24 м =40 10
-----= -----
24 7
800 г к 4 кг = 800:4=200
20 мин к 2 ч = 20:2=10
Х:7=840:2
Х:7=420
Х=420•7
Х=2940
Х•8=960:10
Х•8=96
Х=96:8
Х=12
1)5x-20=x+8<br />5x-x=8+20<br />4x=28<br />x= 28:4<br />x=7<br /><br />2) 9-7x-21=5-6x<br />7x-6x=5-9+21<br />x=17<br /><br />3)2.4-0.4y=3.5-1.5y-1.9<br />-0.4y+1.5y=3.5-1.9-2.4<br />1.1y=-0.8<br />y=-0.8:1.1<br />y=-0.72