standard_description: Solve two-step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding. (This standard is limited to problems posed with whole numbers and having whole number answers; students should know how to perform operations in the conventional order when there are no parentheses to specify a particular order (Order of Operations).)
problem_activity: A bakery sells small cakes for
$${ {{$1}}0}$$
each. At this price, the bakery typically sells
$${100}$$
cakes per week.
The owner of the bakery wants to increase the price of the cake in order to maximize revenue. She determines that for each
$${{$1}}$$
increase in price, she sells
$$5$$
fewer cakes per week.
a.  Which function represents the weekly revenue,
$${R(x)}$$
, the owner of the bakery can expect to earn from the cakes based on
$$x$$
increases in price by
$${{$1}}$$
.
i.
$${R(x)}=(10-x)({100}+5x)$$
ii.
$${R(x)}=(10+x)({100}-5x)$$
iii.
$${R(x)}=(10-5x)({100}+x)$$
iv.
$${R(x)}=(10+5x)({100}-x)$$
b.  At what price will the owner of the bakery earn the maximum weekly revenue from sales of the small cakes?


aligns: no