Question 14723
You might want to review the "zero products principle" which states:

If a*b = 0, then either a = 0, or b = 0, or both.

Apply this principle to your problem:

If (x+6)(2x-1) = 0, then either (x+6) = 0, or (2x-1) = 0, or both.

If (x+6) = 0, then x = -6
If (2x-1) = 0, then x = 1/2

The two solutions are:

x = -6
x = 1/2