A social networking site recorded that 80% of the people who became members of the site one month were between 30 and 40 years old. The equation below represents this information, where x represents the total number of people who became members of the site that month.

x = 0.8x + 72

How many people who became members of the site that month were between 30 and 40 years of age?
Answers:
112
288
360
432
~Please explain, I don't get it.~

Question

A social networking site recorded that 80% of the people who became members of the site one month were between 30 and 40 years old. The equation below represents this information, where x represents the total number of people who became members of the site that month.

x = 0.8x + 72

How many people who became members of the site that month were between 30 and 40 years of age? 
Answers:
112
288
360
432
~Please explain, I don't get it.~

anonymous · Answer

What you need to do is plug in each of the answer choices into the equation given, and if the  result equals the number you plugged in, that's your answer.

So for A, here's what you do:

0.8(112)+72=161.6
Since 161.6 does not equal 112, A is not your answer. 

Do you understand?

anonymous · Answer

Nevermind, I think I understand, correct me if I'm wrong.
0.2=72
x=72/.2=360
360*.8=288?

anonymous · Answer

If you are saying the answer is 288, you are incorrect.

anonymous · Answer

Oh, I thought I had it. I'll do what you said.

anonymous · Answer

alright, if you'd like, you can post what you get here so I can make sure you got it correct :)