The point C lies between A and B on AB. If AC = 7cm and CB = 12cm, find the length of AB. 0 10 cm
20 cm
0 19 cm
O 5 cm

your answer is c:19

Step-by-step explanation:

all you do is add the lengths of AC witch is 7 and CB witch is 12.

add them up you get 19

19 cm

Step-by-step explanation:

AC = 7 cm

CB = 12 cm

therefore

AC + CB = AB

7 + 12 = 19

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional