I'm stuck on bWhen bicycles are sold for $300 each, a cycle store can sell 70 in a season. For every $25 increase in the price, the number sold drops by 10.

a) Represent the sales revenue as a function of the price.

b)The total sales revenue is $17,500. How many bicycles were sold? What is the price of one bicycle?

c) What range of prices will give a sales revenue that exceeds $18,000?

R= revenue

n= number of bikes

p= price

For a

Price| Number of Bikes sold

300 | 70

325 | 60

350 | 50

So find the slope

$\displaystyle \frac{(70-50)}{(300-350)}=-0.4$

Plug that into y=mx+b

$\displaystyle 70=-0.4(300)+b$

$\displaystyle 70=-120+b$

$\displaystyle 70+120=190$

$\displaystyle b=190$

So that means the function to find n(number of bicycles sold) is $\displaystyle -0.4p+190$

Since Revenue is $\displaystyle r=n*p$ then part a is $\displaystyle r=p(-0.4p+190)$ which simplifies to $\displaystyle r=-0.4p^2+190p$

So to solve part b?

$\displaystyle 17500=-0.4p^2+190p$