Question

1) If B is between A and C, AB=10 and AC=28, what is the value of BC?

9

18

19

38

2) If B is between A and C, AB=6x, BC=8x and AC=42, what is the value of x?


3

14

18

24

3) If B is between A and C, AB=2x-1, BC=3x+5 and AC=24, what is the value of AB?

4

7

12

17

Answer 1

One

AB + BC = 28

AB = 10

10 + BC = 28

BC = 28 - 10

BC = 18

Two

AB + BC = AC

AB = 6x

BC = 8x

6x + 8x = 42

14x = 42

x = 42/14 = 3

Three

AB = 2x - 1

BC = 3x + 5

AB + BC = 24

2x - 1 + 3x + 5 = 24

5x + 4 = 24

5x = 24 - 4

5x = 20

x = 20/5

x = 4

AB = 2x - 1

AB = 2*4 - 1

AB = 7