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If x^2 + 2xy + y^2 = 25, then (x + y)^3 could be
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21 Jun 2017, 02:21
21 Jun 2017, 02:21
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Question Stats:
97% (00:34) correct
2% (00:30) wrong based on 109 sessions
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If \(x^2\) + 2xy + \(y^2\) = 25, then \((x + y)^3\) could be
A) 5
B) 15
C) 50
D) 75
E) 125
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Re: If x^2 + 2xy + y^2 = 25, then (x + y)^3 could be
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05 Aug 2017, 06:36
05 Aug 2017, 06:36
2
Carcass wrote:
If \(x^2\) + 2xy + \(y^2\) = 25, then \((x + y)^3\) could be
A) 5
B) 15
C) 50
D) 75
E) 125
Given: x² + 2xy + y² = 25
Factor to get: (x + y)(x + y) = 25
So: (x + y)² = 25
We can conclude that EITHER x + y = 5 OR x + y = -5
This means that EITHER (x + y)³ = (5)³ = 125 OR (x + y)³ = (-5)³ = -125
Answer:
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Re: If x^2 + 2xy + y^2 = 25, then (x + y)^3 could be
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20 Jan 2024, 14:04
20 Jan 2024, 14:04
1
From how I see it... we know that x^2 + 2x + y^2 = (x + y)(x + y) = 25. Thus we can conclude that (x + y) = 5. Hence, (x + y)^3 = 25*5 = 125
