Question

what is the length of CD? A)5 B) 4 C)3 D) 6 HELP!!

Answer 1

do you have a diagram ?

Answer 2

here

Answer 3

both triangles are similar.
x/(20-x) = 7/21
solve for x

CD is x

Answer 4

the answer choices are A) 5 B) 4 c)3 D) 6

Answer 5

x/(20-x) = 7/21
x/(20-x) = 1/3
cross multipy, get
3x = 20 -x
..........
..........
..........
x = ... ?

Answer 6

5!

Answer 7

right?

Answer 8

can you help me on one more?please!

Answer 9

3x = 20 -x
3x+x = 20
4x = 20
x = 20/4 = 5

you are right :)

Answer 10

sure, post your question

Answer 11

wwhat is the length of AC? A) 136 B) 72 C) 132 D) 96 !!!

Answer 12

that is same like before.

x/(144-x) = 3/51
solve for x, first
then calculating the value of AC with AC = 144-x

Answer 13

?

Answer 14

i dont understand :(!

Answer 15

x/(144-x) = 3/51
x/(144-x) = 1/17
cross multiply, get
17x = 144-x
......
......
x = ... ?

Answer 16

what should you do, to get x if you have an equation :
17x = 144-x

Answer 17

i got 9 but that doesnt match to my answer choices !

Answer 18

well, see how to solving for x
17x = 144-x
add by x to both sides, get
17x + x = 144-x+x
18x = 144
divided by 18 on both sides, get
18x/18 = 144/18
x = 8

Answer 19

now, the question asking about AC.
AC = 144 - x
put x = 8, get
AC = 144 - 8 = 136

Answer 20

hoped that make sense

Answer 21

thank u

Answer 22

you're welcome