A store is discounting all regularly priced items by 25%. (i) Find a function f that computes the sale price of an item having a regular price of x. (ii) Find t

Question

A store is discounting all regularly priced items by 25%. (i) Find a function f that
computes the sale price of an item having a regular price of x. (ii) Find the regular price
of an item that costs $72.88 on sale.

Answer 1

(i)  f(x) = 0.75x

 

(ii) Regular price  x  0.75 = Sale price

 

Regular price = 72.88/0.75 = $97.17

Answer 2

Hi Keith;

25%=0.25

x=regularly priced items

d=discount

f(d)=x-xd

f(d)=x(1-d)

f(0.25)=x(1-0.25)

$72.88=x(1-0.25)

$72.88=(0.75)x

Let's divide both sides by 0.75...

($72.88)/(0.75)=[(0.75)x]/(0.75)

$97.17=x