Answer:
see below
Step-by-step explanation:
11a -2(x^2 -3)
Distribute
-2*x^2 -2(-3)
-2x^2 +6
11b 2x(x+4)
Distribute
2x*x +2x*4
2x^2 +8x
12 The perimeter is the sum of all sides
The top is equal to the bottom and the left side is equal to the right
x-10 + x+20+x-10+x+20
Combine like terms
4x +20
