-4(-3+-6+-20)=

Solution for -4(-3+-6+-20)= equation:

-4(-3+-6+-20)=0

We simplify the equation to the form, which is simple to understand 
-4(-3+-6+-20)=0

Simplifying terms in parentheses
-4*(+-6+-20-3)=0

Reorder the terms in parentheses
+(-0-0+12)=0

Simplifying terms in parentheses
+(+12)=0

Remove unnecessary parentheses
+12=0

We move all terms containing  to the left and all other terms to the right. 
0=0-12

We simplify left and right side of the equation. 
0=-12

0=-12

The left and right sides are not equal, therefore there is no solution. This equation is invalid.