Please confirm if I did the follow problems correctly:

Question

A) Find the sum or difference.
(5a – 3b) + (2a + 6b)= 7a + 9b
Answer: = 7a + 9b
B) Let’s work a few of these (FOIL)
1) (x+2) (x+8) = x 10
Answer: x10
2.) (x+5) (x-7) = x + 11
Answer: x + 11
3.) (2x+4) (2x-3) = 4x + 7
Answer: 4x + 7

Answer 1

A) 7a + 6b (3b is negative)

B) These are indicating that you need to multiply. (I don't know what "FOIL" means.)

1) (x+2) (x+8) = x^2 + 10x + 16

I'll let you use that same process to find the remaining answers.