Question

if 3x -4y =10and xy=-1 find 9x²+16x²

Answer 1

(3x-4y)^2= 100
9x2+ 16y2 -24xy= 100
9x2+16y2-24(-1)=100
9x2+16y2=100-24=76

Answer 2

Heya,

Given =>

3x - 4y = 10

And xy = -1

We have to find,
9x² + 16y² = ?

So,

=> 9x² + 16y²

=> (3x)² + (4y)²

=> (3x - 4y)² + 2(3x)(4y)

=> (10)² + 24xy

=> 100 + 24(-1)

=> 100 - 24

=> 76

Therefore,

9x² + 16y² = 76

Hope this helps....:)