SOLUTION: Hi, Can you help me with the following problem? I don't understand how I'd set the equation up. Li Teng is ordering graduation announcements for the senior class. If 100 announcem

Algebra ->  Equations -> SOLUTION: Hi, Can you help me with the following problem? I don't understand how I'd set the equation up. Li Teng is ordering graduation announcements for the senior class. If 100 announcem      Log On


   



Question 1015712: Hi,
Can you help me with the following problem? I don't understand how I'd set the equation up. Li Teng is ordering graduation announcements for the senior class. If 100 announcements are ordered, the cost is $225. The cost for 175 announcements is $375, and 200 announcements cost $425. Write an equation to describe this relationship and use it to find the cost of 250 announcements.
Thanks!

Answer by FrankM(1040) About Me  (Show Source):
You can put this solution on YOUR website!
100 cost $225
175 cost $375
200 cost $425
First, since cost for 200 is not twice the cost for 100, there's more going on.
The 75 from 100-175 are $150 extra or $2 each
The 25 from 175-200 are $50 extra or $2 each
From this we see that we have a linear equation but not "Direct Variation". DV is when Y=MX, with an intercept at 0. In this case we need to get the Y intercept, which effectively describes a setup fee. The cost before we actually buy the first card.
We already know cards cost $2 each. Since 100 cost $225, it's a $25 fee
So the equation is Cost = $25 + $2per card.
250 cards will cost $525.