Answer:c=8
Explanation:
AB + BC = AC
6c-8 + 3c+1 =65 (simplify)
9c -7 =65 (combine like terms) (cancel out the -7 by adding 7 to both sides).
9c = 72 (Divide both sides by 9 to get c by itself.
c=8
Then substitute c for 8
AB = 6(8)-8 = 40
BC = 3(8)+1 = 25
AC = 40 + 25 =65