Bonjour,
a. 2x-2=2
2x=2+2
x=4/2=2
b. 3z-10=11
3z=11+10
z= 21/3=7
c. -y+1=0
-y=-1
t=1
d. 5x+1=-39
5x=-39-1
x= -40/5= -8
f. -y+6=-2.3
-y=-2.3-6
-y= -8.3
y= 8.3
g. -3x+7=-22
-3x=-22-7
x= -29/-3
x= 29/3
h. 6z+5=-11
6z=-11-5
z=-16/6= 8/3
i. -x-9=11.2
-x=11.2-9
-x=2.2
x= - 2.2
j. 9.7y-5.7=-1.7
9.7y=-1.7+5.7
y= 4/9.7