a) 3x + 4 = 2 + 9
3x + 4 = 11
3x = 7
x = 7/3
b) 2x + 3 = 3-5
2x + 3 = -2
2x = -5
x = -5/2
x = -2,5
c) 5x -1 = 2 + 4
5x -1 = 6
5x = 7
x= 7/5
d) 3x + 1 = 7+ 5
3x +1 = 12
3x = 11
x = 11/3
e) 5x+8=0
5x= -8
x= -8/5
f) 5-4x= 0
-4x= -5
-x= -5/-4
-x= 5/4
x= -5/4
g) 5x+2=9+7
5x+2= 16
5x= 14
x= 14/5