Answer:
a)
[tex]p(r)=(r-5)\cdot 1.05[/tex]
b)
[tex]p(15.50)=(15.50-5)\cdot1.05=10.50\cdot1.05=11.025\approx11.03\ \$[/tex]
Step-by-step explanation:
a)
Assume that r is a regular price before discount and tax
Including discount, we substract 5 from r. We get (r-5).
Then, we include tax by adding 5% value of (r-5)
Including a tax we may realize by multiplying initial value (r-5) by 1.05, where an ending .05 is percentage value of a tax
b)
in a formula [tex]p(r)=(r-5)\cdot 1.05[/tex] we substitute r=15.50 and calculate the value on the right side of the sign "=".
You solve it too, using a calculator.
If you push the following buttons:
1 5 . 5 0 - 5 = + 5 %
you should get a result 11.025, after approximation to the 2 digits after comma there is 11.03
