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?

1. 112
2. 288
3. 432

My answer was 360 but that was wrong

Answer 1

@satellite73

Answer 2

@zepdrix

Answer 3

@Luigi0210

Answer 4

@Preetha

Answer 5

@wolfe8

Answer 6

@agent0smith

Answer 7

Is that x or y on the left side?

Answer 8

x

Answer 9

Oh well you just have to subtract both sides with 0.8x first

Answer 10

so then I have x - 0.8x = 72

Answer 11

Yeah and what does the left side simplify to?

Answer 12

1.8x?

Answer 13

*1.2x

Answer 14

*0.2x, sorry bad key board

Answer 15

So now you have 0.2x=72
You now divide both sides with 0.2 to get only x on the left side

Answer 16

x = 360

Answer 17

oh so its 288, I forgot to subtract 20%