Answer:c
Step-by-step explanation:
What you have to do is just add 18 plus what equals to 20 so you would get 2
1. All negative numbers added together are still negative
2. There is a proof and a theorem for it.
3. If it is an animal, then it has fur
12 ft * 10 ft = 120 sq ft
½ * 6 ft * 7 ft = 21 sq ft
120 sq ft - 21 sq ft = 99 sq ft (it is area of the composite shape)