2x-√7y =10 and xy=√7 . Find the value of 4x²+7x²
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нєℓℓσ мαтє
There is small error in your question.
It will be 4x² + 7y² not 4x² + 7x²
нєяє ιѕ уσυя ѕσℓυтισи
2x - √7y = 10 [ Given ]
xy = √7 [ Given ]
Now, on squaring both sides we get.
( 2x - √7y )² = 10²
4x² + √7y² - 2( 2x)( √7y ) = 100
4x² + 7y² - 4√7xy = 100
4x² + 7y² - 4√7( √7 ) = 100
4x² + 7y² - 28 = 100
4x² + 7y² = 128
нσρє ιт нєℓρѕ
There is small error in your question.
It will be 4x² + 7y² not 4x² + 7x²
нєяє ιѕ уσυя ѕσℓυтισи
2x - √7y = 10 [ Given ]
xy = √7 [ Given ]
Now, on squaring both sides we get.
( 2x - √7y )² = 10²
4x² + √7y² - 2( 2x)( √7y ) = 100
4x² + 7y² - 4√7xy = 100
4x² + 7y² - 4√7( √7 ) = 100
4x² + 7y² - 28 = 100
4x² + 7y² = 128
нσρє ιт нєℓρѕ
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