Mathematics
If x2 + 4y2 = 4xy, then x : y is :
1 : 1
1 : 2
1 : 4
2 : 1
Ratio Proportion
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Answer
Given,
x2 + 4y2 = 4xy
Dividing the equation by y2,
Let . Then
⇒ k2 + 4 = 4k
⇒ k2 - 4k + 4 = 0
⇒ k2 - 2k - 2k + 4 = 0
⇒ k(k - 2) - 2(k - 2) = 0
⇒ (k - 2)(k - 2) = 0
⇒ (k - 2)= 0 [Using Zero-product rule]
⇒ k = 2
Therefore,
Hence, option 4 is the correct option.
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