Question

3x-4y=10 and xy = -1, find the value of 9x2 + 16y2

Answer 1

square both side of the eqn 3x-4y=10
9x^2+16y^2-2(3x)(4y)=100
9x^2+16y^2=100+24xy
value of xy=-1
9x^2+16^2=100+24(-1)=76. answer.
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