Hi there! :)
Answer:
![\huge\boxed{BC = 26}](https://img.qammunity.org/2021/formulas/mathematics/college/s8pai6x4fmccv7e63asfu80y7oo2y0lgqp.png)
In the question, it is given that AB = 3x - 1 and AC = 8x - 20.
Since AB = 3x - 1 and B is the midpoint, this means that BC is also 3x - 1. We can express this as an algebraic equation:
8x - 20 = 2(3x - 1)
Distribute the 2 with terms inside of the parenthesis:
8x - 20 = 6x - 2
Subtract 6x from both sides:
2x - 20 = -2
Add 20 to both sides:
2x = 18
Divide both sides by 2:
x = 9
Solve for BC by plugging in the value of x into the formula for AB
(since AB ≅ BC):
3(9) - 1 = 27 - 1 = 26 units.
BC = 26 units.