Answer:

Step-by-step explanation:
So we have the equation:

First, distribute the 7 into the (x+8) and simplify:

Combine the like terms 7x and 8x by adding them together:

Subtract 56 from both sides to isolate the x:

Divide both sides by 15 to get x:

Answer:
-2(x^2+2)
Step-by-step explanation:
1. x^2-3x^2-4
= -2x^2-4
2. -2(x^2+2) factor completely :)