Răspuns:
Ex. 3
a) 3x = -60
x = -20
b) -3x = - 12
x = 4
c) -18 = 2x
x = -9
d) 2x = 70
x = 35
e) 2x = -4
x = -2
f) 4x = 36
x = 9
Ex. 4
a) x = -30
b) x = 3
c) 2x = -7 • 3 - 1
2x = -24
x = -12
d) -x = 12 • 4 - 2
-x = 46
x = -46
e) x = - 3
f) 3x = -1 • 3 • 2
3x = -3 • 2
3x = -6
x = 2
Ex. 5
a) 3x + 3 - 2x = 6
x = 6 - 3
x = 3
b) 4x + 6 = 2x + 2
2x = 2 - 6
2x = - 4
x = -2
c) x = 0
d) 5x - 7 = 2x + 4x - 4
5x - 7 = 6x - 4
-x = - 4 + 7
-x = 3
x = -3
e) 3x - 3 + 9 = 2x + 2 - x
3x - 3 + 9 = x + 2
2x = 2 - 9 + 3
2x = -4
x = -2
f) 1 + 2x - 2 = 4 + 3x - 6
2x - 3x = -2 + 1
-x = -1
x = 1
Ex. 6
a) x = 1
b) ?
c) ?