Question

3(×-1)=15
6(×+7)=54
5(×+2)=20
72=8(×-1)
4(×-7)=28

Answer 1

x-1=15/3
x-1=5
x=5+1=6

6(x+7)=54
x+7=9
x=9-7=2

5(x+2)=20
x+2=4
x=4-2=2

72=8(x-1)
x-1=9
x=9+1=10

4(x-7)=28
x-7=7
x=7+7=14

Answer 2

[CAZUL1] 3(x-1)=15=>x-1=15/3=5=>x=5+1=6
[cazul2]
6(x+7)=54=>x+7=54/6=9=>x=9-7=2
[cazul3]
5(x+2)=20=>x+2=20/5=4=>x=4-2=2
[cazul4]
72=8(x-1)=>72/8=x-1=>9=x-1=>9+1=x=>10=x
[cazul5]
4(x-7)=28=>x-7=28/4=7=>x=7+7=14
R:1.x=6
2.x=2
3.x=2
4.x=10
5.x=14