<span>6x=480 ft
x=80 ft.
Area = x^2 = 80^2 = 6400 sq. ft.</span>
Your identity says ...
... sum of cubes = (sum)³ -3(product)(sum)
... = 4³ -3·1·4
... = 64 -12 = 52
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The two numbers are 2±√3, and the sum of their cubes is indeed 52.
It is always important to go through the given problem first to get a concept of the requiremement. Then all the information's available from the question has to be noted down in such a manner that there would be no need to look at the question while solving.
Total number of students wearing jeans = 10
Total number of students wearing shorts = 9
Total number of students wearing capris = 2
Then the total number of students surveyed by Mrs Lane = (10 + 9 + 2)
= 21
Now percentage of students wearing shorts = (9/21) * 100
= (3/7) * 100
= 300/7
= 42.85 percent
So a total percentage of 42.85% of the students were wearing shorts.
The answer is -19 1/2 feet