SOLUTION: The movie screen in the Imax theater in Sydney, Australia is 11349 square feet in area. If the screen is 20 feet longer than it is wide, find the dimensions of the screen

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Question 269176: The movie screen in the Imax theater in Sydney, Australia is 11349 square feet in area. If the screen is 20 feet longer than it is wide, find the dimensions of the screen
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let a = length
Let b = width
given:
a+=+b+%2B+20
ab+=+11349
By substitution:
%28b+%2B+20%29%2Ab+=+11349
b%5E2+%2B+20b+=+11349
I'll solve by completing the square
b%5E2+%2B+20b+%2B+%2820%2F2%29%5E2+=+11349+%2B+%2820%2F2%29%5E2
b%5E2+%2B+20b+%2B+100+=+11349+%2B+100
%28b+%2B+10%29%5E2+=+11449
Take the square root of both sides
b+%2B+10+=+107
b+=+97
And, since
a+=+b+%2B+20
a+=+117
The length is 117 ft and the width is 97 ft
check:
ab+=+11349
97%2A117+=+11349
11349+=+11349
OK