Answer
(B)
Work Step by Step
Step 1. For equation-A, we have $2x+2x+4=20$, $4x=16$, thus $x=4$
Step 2. For equation-B, we have $2x+10+2x=-2$, $4x=-12$, thus $x=-3$
Step 3. For equation-C, we have $8x+16+4x=16$, $12x=0$, thus $x=0$
Step 4. For equation-D, we have $2x+2x-6=10$, $4x=16$, thus $x=4$
Step 5. We can see that equation-B gives a negative solution which can not be true for the length of a side.
