To solve the equation, we follow the order of operations (also known as PEMDAS/BODMAS):
First we simplify the expression inside the parentheses:
1 - 15 = -14
Next, we apply multiplication and division from left to right:
-2(1 - 15) = -2(-14) = 28
Finally, we perform subtraction:
13 - 28 = -15
Therefore, 13 - 2(1 - 15) / 4 equals -15.