Let's see.
Let's start with the parentheses.
1-15=-14
The equation is now: 13-2(-14)/4
Now multiply -2 by -14
-2*-14=28
The equation is now 13+28/4
divide by 4
the equation is now 13+7
add
13+7=20
So the equation simplifies to 20.
Can you please tell me what order you did your operations in? I would love to know, thanks!