Question

please help me! :^) I need help with #8. It says:
A farmer owns a triangular field with a perimeter of 9a + 4b - 5. Which of the following could be side lengths of the field?

a: 3,-2+2b,2b+9a
b: 3a,3a+5, and 4b
c: 8a,1a+3b, and b-5
d: 9,4b, and -5a

Answer 1

It's number C, because if you get the sum of the expressions you get the perimeter of 9a + 4b - 5.

Answer 2

C. 8a,1a+3b and b-5
because
P=8a+1a+3b+b-5=9a+4b-5