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Divisors and integers
Posted: 28/12-2010 13:57
by Oddis88
My backyard is a rectangle with area 480 square feet and its length and width are both an integer number of feet. if both dimensions are greater than 7 feet and the length is longer than the width, how many possible lengths are there for my backyard?
Posted: 28/12-2010 18:34
by Janhaa
Sikkert en fix måte å gjøre dette på, jeg primtallsfaktoriserte 480. Dvs
[tex]480=2^2\cdot 2^2\cdot 5\cdot 6=2^5\cdot 3\cdot 5[/tex]
Hvis l, b > 7 og l > b og l*b = 480, fås 6 lengder (l)
(l, b) = (24, 20), (30, 16), (32, 15), (40, 12), (48,10), (60, 8)
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tok den litt på hælen - her nede i syden...
Posted: 28/12-2010 19:50
by Oddis88
Selvfølgelig helt rett ^^