hi! for x, you need to do 2x-8 = x+17 and solve, because since b is the midpoint, ab and bc would be congruent.
2x-8 = x+17
1x-8 = 17
1x = 25
x = 25
in order to find ab, you plug in the x into the expression.
ab = 2x-8
ab = 2(25)-8
ab = 42
do the same for bc:
bc = x + 17
bc = 25 + 17
bc = 42
and for ac, combine the two expressions and plug in the value for x.
ac = ab + bc
ac = 2x-8 + x+17
ac = 2(25)-8 + 25+17
ac = 84
i hope this helped! have a good day/night :)
