Question

if 3 x minus 4 Y is equal to 10 and x y equal to minus 1 find the value of 9 X square + 16 y square

Answer 1

Hi ,

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We know the algebraic identity

a² + b² - 2ab = ( a - b )²

Or

a² + b² = ( a - b )² + 2ab

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It is given that ,

3x + 4y = 10 ----( 1 )

xy = -1 --------( 2 )

Now ,

( 3x )² + ( 4y )² = ( 3x - 4y )² + 2(3x)(4y)

9x² + 16y² = ( 3x - 4y )² + 24xy

= ( 10 )² + 24 × ( -1 )

= 100 - 24

= 76

I hope this helps you .

: )

Answer 2

not sure. but I think it will help you