2.9х-1.1х=5.04 ; ...

Мария

1)2.9х-1.1х=5.04

1.8х=5.04

х=2.8

2)0.8(х-1.9)=0.56

0.8х-1.52=0.56

0.8х=2.08

х=2.6

3)7х+9х+0.32=2.72

16х+0.32=2.72

16х=2.4

х=0.15

4)5у+7у-0.024=0.204

12у=0.228

у=0.019

5)0.11х+0.08х=45.6

0.19х=45.6

х=240

6)0.8(100-0.04х)=8.64

80-0.032х=8.64

-0.032х=-71.36

х=2230

7)17(5х-0.16)=0.238

85х-2.72=0.238

85х=2.958

х=0.0348