If 1/x + 1/y = 5 , and xy = 6 , then (x+y)^2 = ?
A) 800 B) 900 C) 880 D) 9800
Explanation will be appreciated. B/W is there a way i can appreciate someone's answer here. I mean give somebody a point for their contribution ???
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Algebra Problem
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1/x+1/y = (x+y)/xy = (x+y)/6 = 5
x+y = 30
(x+y)^2 = 900
x+y = 30
(x+y)^2 = 900
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1/x + 1/y = 5
Simplify 1/x + 1/y:
1/x + 1/y = (x+y)/xy
therefore:
(x+y)/xy = 5
cross-multiply:
(x+y) = 5*xy
Given that xy = 6, substitute the value for xy:
(x+y) = 5*6 = 30
Hence:
(x+y) = 30
(x+y)^2 = (30)^2
(x+y)^2 = 900
Ans choice B
Simplify 1/x + 1/y:
1/x + 1/y = (x+y)/xy
therefore:
(x+y)/xy = 5
cross-multiply:
(x+y) = 5*xy
Given that xy = 6, substitute the value for xy:
(x+y) = 5*6 = 30
Hence:
(x+y) = 30
(x+y)^2 = (30)^2
(x+y)^2 = 900
Ans choice B
