15 = -3(2x - 1)
15 = -3*2x -3*(-1)
15 = -6x + 3
15 - 3 = -6x |*(-1)
-12 = 6x |:6
x = -2
The solution of this equation is very simple. Simply move an unknown to one side, and known to the other. Then the number of the right divided by the number of standing by the unknown and this is the result.
