SOLUTION: A rectangular countertop has an area of 15 ft^2. If the width is 3.5 shorter than the length, what are the dimensions of the countertop?

Algebra.Com
Question 1087935: A rectangular countertop has an area of 15 ft^2. If the width is 3.5 shorter than the length, what are the dimensions of the countertop?
Answer by ikleyn(52794)   (Show Source): You can put this solution on YOUR website!
.
Answer. 6 and 2.5 ft. 

To solve it MENTALLY, consider rectangle with doubled dimensions.

Then the area is 15*4 = 60 ft^2, and the difference L - W = 7 ft.


Now find (MENTALLY) two factors of 60 that differ in 7 (=2*3.5) ft.


They are 12 and 5.


Now divide 12 and 5 by 2 to return to the original dimensions.


You will get 6 and 2.5.

Solved (MENTALLY).


The alternative way is to solve a quadratic equation with decimal coefficients.



RELATED QUESTIONS

A rectangular countertop has an area of 15 ft ^2. If the width is 3.5 ft shorter than the (answered by josgarithmetic)
If a rectangular kitchen has an area of 160 ft.² and the length is 12 feet more than the (answered by Alan3354,josgarithmetic)
A rectangular countertop has an area of 27 square feet. Its perimeter is 24 feet. What... (answered by Cromlix)
A rectangular Home lot has an area of 240 ft.². it’s width is shorter than its length by (answered by josgarithmetic)
If a garden has an area of 252 ft^2. Its length is 4 ft more than its width. What are... (answered by stanbon)
The area of a rectangular tabletop is 6 square feet. If the width is 2 feet shorter than (answered by oberobic)
the area of a granite countertop is 12x^2+10x-12. the width of the countertop is 2x+3.... (answered by flame8855)
a sign has a area of 60ft squared. if the width of is 4 ft shorter then the length, what... (answered by ankor@dixie-net.com)
A rectangular room has an area of 400 sq. ft. The length is 7 ft. less than twice the... (answered by nyc_function)