Question

if 3x -4y=10 and xy =-1 ,then find 9 x square+ 16 y square

Answer 1

9x^2 +16y^2
= (3x-4y)^2 +2xy
Now we will put the value of 3x-4y as 10 and xy as -1 in
(3x-4y)^2 +2xy

= (10)^2 +2 (-1)
= 100 -2
= 98.

So,9 x square+ 16 y square equals 98.