a)
1,5 + x = 4,25
x = 4,25 - 1,5
x = 2,75
b)
5x + 5 = 50
5x = 50 - 5
5x = 45 | : 5
x = 9
c)
5x - 6 + 2x - 1 = 14
5x + 2x = 14 + 6 + 1
7x = 21 | : 7
x = 3
d)
7 - 6x = 49
-6x = 49 - 7
-6x = 42 | : (-6)
x = -7
e)
-8 · 2x - 10 = 22
-16x = 22 + 10
-16x = 32 | : (-16)
x = -2