由4x-3y-6z=0及x+2y-7z=0得
x=3z,y=2z,(z≠0)
代入代数式,
(5x²+2y²-z²)/(2x²-3y²-10z²)
=(45z²+8 z²-z²)/(18 z²-12 z²-10 z²)
=52÷(-4)
= -13.