Qq peux m’aider svp ?

1=-7x
x=1/(-7)

-4=5x/3
(-4)*3=5x
-12=5x
x=5/(-12)

-2x+4=0
-2x=-4
2x=4
x=4/2
x=2

3/7 -2x/5 = 1/3
3/7 -2x = (1/3)*5
3/7 -2x = 1/6
-2x = 1/6 - 3/7

5=-x/3
-x= 5*3
-x=15
x= -15

2-x = 1/5
-x = 1/5-2
-x= -1.8
x=1.8