If b is the midpoint of AC and AC=8x-20, then find BC

Answer 1

If B is the midpoint of AC, then AB = BC.

Since AB = 3x - 1, then BC = 3x - 1

By segment addition postulate:

AB + BC = AC

AC is given as 8x - 20

substituting:

3x - 1 + 3x - 1 = 8x - 20

6x - 2 = 8x - 20

18 = 2x

x = 9

BC is given as 3x + 1, so substituting 9 for x:

3(9) - 1 = 26

Answer 2

Answer 3

AC = 8x-20 = 2BC = 2(3x-1) = 6x -2

8x-20 = 6x-2

8x-6x = -2+20

2x = 18

x = 18/2 = 9

x= 9

BC =3x -1 = 3(9)-1 = 27-1 = 26

BC =26