Iam stuck on this algebra question:

a homeowner wants to increase the size of his deck that now measures 15 feet by 18 feet. his homeowner's association declares that no deck is to be more than 928 square feet. if the length and the width of the deck are to be increased by the same amount, find, to the nearest tenth, the maximum number of feet by which the length of the deck may be legally increased.

a) 14 feet
b)21 feet
c)28 feet
d)32 feet

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98