Question

Найдите (x² + y² + z²)/(xy + yz + xz), eсли x/2=y/5=z/6

Answer 1

Y=5x/2  z=6x/2=3x
Подставляем:
(x^2+25x^2/4+9x^2)/(5x^2/2+15x^2/2+3x^2)= (1+25/4 +9)/(5/2+15/2+3)=(65/4)/13=5/4
Ответ:5/4