a) 5 * x - 3 + 2 * x = 4 * x + 9
7x - 3 = 4x + 9
7x - 4x = 9 + 3
3x = 12 / : 3
x = 4
b) 8 * x - 6 -9 * x = 5 * x - 6
8x - 9x = 5x
-x = 5x
-x-5x = 0
-6x = 0 / : -6
x = 0
c) 2 + 4 * x - 1 + 2 * x = -8 + 4 * x - 7
2 - 1 + 2x = -8 - 7
1 + 2x = -15
2x = - 15 - 1
2x = -16 / : 2
x = -8
d) -3 + 7 * x - 2 = 3 * x - 11 + 6 * x
-5 + 7x = 9x - 11
7x - 9x = -11 + 5
-2x = -6 / : -2
x = 3
e) 4 + 5 * x - 2 = 7 * x - 7
2 + 5x = 7x - 7
5x - 7x = -7 - 2
-2x = -9 / : -2
x = 9/2 = 4 całe i 1/2
f) -8 + 7 * x + 3 = 5 * x + 4 + 4 * x + 5
-5 + 7x = 9x + 9
7x - 9x = 9 + 5
-2x = 14 / : -2
x = -7
