You get everything you need from factoring the last expression:

The left side is a difference of squares, and we get another difference of squares upon factoring. We end up with

Plug in everything you know and solve for
:

Answer:C=15
Step-by-step explanation:
Just do math
Answer:
what? if u mean by rounding, its 103
Find a common denominator 7/8 = 35/40 and 5/10 = 20/40. Also 7/8 is almost a whole and 5/10 is half. 7/8 is greater.
Alright so I got A=4, B=5 and C=9
A B C
+ A C B
----------
C B A
459
+ 495
--------
954