Answer:
ab = 29, bc = 27
Step-by-step explanation:
If we assume that point b lies on line segment ac between points a and c, then the segment sum theorem tells us ...
ab + bc = ac
(4x +9) + (5x +2) = 56 . . . . substitute given values
9x +11 = 56 . . . . . collect terms
9x = 45 . . . . . . . . subtract 11
x = 5 . . . . . . . . . . divide by 9
Then the segment lengths are ...
ab = 4·5 +9 = 29
bc = 5·5 +2 = 27
