posted by yessenia .
If B is between A and C, AB=5y+4, BC=7y-3, and AC=20y-7. Find the value of y, AB, BC, and AC.
after making a diagram
it is clear that
20y-7 = 5y+4 + 7y-3
solve this for y, then sub it into the expressions given.
check: you should get 13 for AC