Step-by-step explanation:
it all starts with the understanding that "midpoint" means that the line segments on both sides have the exact same length.
this is the same as "cut a pizza or a cake in half".
therefore, we know
10x + 1 = 8x + 13
2x + 1 = 13
2x = 12
x = 6
AB = 10x + 1 = 10×6 + 1 = 60 + 1 = 61
BC = AB but to control : 8×6 + 13 = 48+13 = 61
correct.
AC = AB + BC = 61 + 61 = 122
