Question

Need help please! What is the length of AC?

( Picture attached below )

Answer 1

Use the similarity proof.

Answer 2

triangle ABC is similar to triangle DEC.

Answer 3

\[\frac{ 81 }{ 9 }=\frac{ 140-x }{ x }\]
Corresponding sides in similar triangles.

Answer 4

\[81x=9(140-x)\]
Cross multiply to get what I got above. Now solve for x please.

Answer 5

@Krispyhaha

Answer 6

@Azteck So would it be 9?

Answer 7

\[9x=140-x\]
Solve now...

Answer 8

I'm getting 15.5 I think I'm doing something wrong. I'm bad at this sorry.

Answer 9

\[9x=140−x\]
What happens when you move that -x to the LHS? what changes?

Answer 10

Honestly I don't know. Are we dividing 9 by 140 to get our answer or what exactly?

Answer 11

collect like terms please.

Answer 12

Do you know what "collecting likes terms" is?

Answer 13

No. That's probably the problem isn't it?

Answer 14

Yes. You're meant learnt that at the very beginning of algebra.
You were meant to do questions like this:
\[x+2x=?\]
\[x^2+y+x+2x^2+2y=?\]
I guess you weren't paying attention when you were learning this...

Answer 15

*meant to learn

Answer 16

Yeah your right I forget things easily! Can you show me steps on what to do next so I can move along?

Answer 17

Umm...I can't show yous teps to understand questions like this when you require the basics. Everything in life, require you to learnt he basics by heart before you start doing stuff like this. And if you learn the basics, you won't forget it. Learning is completely different to remembering.

Answer 18

you steps*

Answer 19

learn the*