In some country, the percent of adult blogging has changed within the various age ranges. From 2007 to 2009, the function y=-3x+28 can be used to estimate the percent of adults under 30 who blogged, and the function y=2x+5 can be used to estimate the percent of adults over 30 who blogged. For both functions, x is the number of years after 2007.

A. if this trend continues, predict the year in which the percent of adults under 30 and the percent of adults over 30 who blog was the same.

The percent of adults under 30 and the percent of adults over 30 who blog was the same in the year______?

Question

In some country, the percent of adult blogging has changed within the various age ranges. From 2007 to 2009, the function y=-3x+28 can be used to estimate the percent of adults under 30 who blogged, and the function y=2x+5 can be used to estimate the percent of adults over 30 who blogged. For both functions, x is the number of years after 2007.

A. if this trend continues, predict the year in which the percent of adults under 30 and the percent of adults over 30 who blog was the same.

The percent of adults under 30 and the percent of adults over 30 who blog was the same in the year______?

anonymous · Answer

B. use these equations to predict for the year 2012 the percent of adults under 30 who blog and the percent of adults over 30 who blog.

In 2012, ____% of adults under 30 blog.
In 2012, ____% of adults over 30 blog

anonymous · Answer

@sleepyjess

sleepyjess · Answer

ok, x is the number of years after 2007. so x is 2

anonymous · Answer

ok

anonymous · Answer

is that it?

sleepyjess · Answer

oh, they want 2012

anonymous · Answer

so 
y=-3(2)+28
y=2(3)+5

sleepyjess · Answer

so how many years away from 2007 is 2012?

anonymous · Answer

5 years

sleepyjess · Answer

Yep, so for part b, substitute in 5

anonymous · Answer

ok one moment, i need to work this out real quick

sleepyjess · Answer

ok

anonymous · Answer

y=-3(5)+28=13
y=2(5)+5=15

aum · Answer

For part A, equate the two y equations, solve for x first.  Then add x to 2007 to find the year when the y's will be the same.

sleepyjess · Answer

@aum got to part A before me :)

anonymous · Answer

so 13% of adults under 30 blog
and 15% of adults over 30 blog

Now I need to find the year in part A

aum · Answer

Your answer to part B is correct.

anonymous · Answer

how do i find the percent of adults under 30 and the percent of adults over 30 who blog was the same in the year _______________

sleepyjess · Answer

-3x + 28 = 2x + 5

sleepyjess · Answer

solve for x

anonymous · Answer

13=15   or was I not supposed to replace x

sleepyjess · Answer

Don't replace x, we need to solve for x

anonymous · Answer

so combine like terms?

sleepyjess · Answer

Move all x's to one side, all constants to the other

anonymous · Answer

33=5x

sleepyjess · Answer

Almost, good try. 23 = 5x

anonymous · Answer

ooohhh you subtracted 5, lol i added, my bad

anonymous · Answer

ok do i divide 23/5?

anonymous · Answer

i get 4.6, ohhh so 2007+ 4 years= 2011 ???

anonymous · Answer

?

sleepyjess · Answer

4.6 years, so yeah, I would put 2011

anonymous · Answer

YES, I have been stuck on this question for hours, thank you so much!!! ;D

sleepyjess · Answer

$\LARGE\cal\color{#ff0074}{No~Problem!}\\bbox [10pt, #00ffab,border:5pt solid blue ]{\color{#872AF0}{\huge\cal ~\dagger~\heartsuit sleepyjess~\heartsuit~\dagger}}$