УМОЛЯЮ ПОМОГИТЕ РЕШИТЬ УРОВНЕНИЯ

Question

УМОЛЯЮ ПОМОГИТЕ РЕШИТЬ УРОВНЕНИЯ

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Answer 1

1)0.4(3х+12)=3*5.6

0.4(3х+12)=16.8

3х+12=16.8:0.4

3х+12=42

3х=42-12

3х=30

х=30:3

х=10

2)0.5(15+4х)=2*8.7

0.5(15+4х)=17.4

15+4х=17.4:0.5

15+4х=34.8

4х=34.8-15

4х=19.8

х=19.8:4

х=4.95

3)1.2(3х+1.6)=5*2.4

1.2(3х+1.6)=12

3х+1.6=12:1.2

3х+1.6=10

3х=10-1.6

3х=8.4

х=8.4:3

х=2.8

4)5.4(4.7х-4.2)=0.9*3

5.4(4.7х-4.2)=2.7

4.7х-4.2=2.7:5.4

4.7х-4.2=0.5

4.7х=0.5+4.2

4.7х=4.7

х=4.7:4.7

х=1