X=((12/13)x) -(5/13)y, Y=((5/13)x =(12/13)y) what does this equal? 25X^2 - 120XY +144Y^2 -156X -65Y

Question

This is problem 20 on section 10.5 out of the the math bok: precalulus mathamatics for calculus fifth edition by James stewart

Answer 1

X=((12/13)x) -(5/13)y, Y=((5/13)x =(12/13)y) what does this equal? 25X^2 - 120XY +144Y^2 -156X -65Y

your final expression (25X^2 - 120XY +144Y^2 -156X -65Y ) evaluates to: 169(y^2 - x)