Răspuns:
a) 4x-1 = x+8
4x = x+8+1
4x-x = 8+1
3x = 9
x = 9÷3 = 3
b) x-2 = 3x+6
x= 3x+6+2
x = 3x + 8
x-3x = 8
-2x = 8
x = 8÷(-2) = -4
c) 5-2x = x-4
-2x = x-4-5
-2x = x-9
-2x-x = -9
-3x = -9
x = (-9)÷(-3) = 3
d) 4-5x = 7-2x
-5x = 7-2x-4 = -2x + 7 - 4
-5x = -2x + 3
-5x + 2x = 3
-3x = 3
x = 3 ÷ (-3) = -1