2A)
C is correct.
2B) If x + 13 = 28, solve.
If x = 15 and x + 13 = 28, you can solve it two ways:
1. Plug x into 4x + 26 to get a perimeter of
86, or
2. Redo the equation:
3a. Since the 6z is negative, you want an expression the has 5z - (11z). Answers A and D have that in their answer.
But since the 13 is positive, you want the answer that subtracts the smaller number from the larger. Thus,
D is your answer since it subtracts 2 from 15.
3b) You think about this question the same way; 6z is positive, so the smaller number is being subtracted from the larger, meaning that 11z - 5z is what you look for. C and D are the two that have that, so now let's look at the second term.
The 13 is negative, so you want the answer that has 2 - 15. The answer that has that is
D.
Hope this helps :D