AB is 3(x+1) and BC is x +5. B is the midpoint of AC. Solve for AB.

Question

please someone explain this concept to me, I have no clue how to do this kind of question.

Answer 1

Since B is the midpoint of AC, then AB = AC.

Since AB = 3(x+1) and BC = x+5 and AB = BC, we can say that 3(x+1) = x+5

Solve for x:

3(x+1) = x+5

3x + 3 = x + 5

2x = 2

x = 1

We know AB = 3(x+1) and that x = 1, so

AB = 3(1 + 1) = 3*2 = 6