Question

(1/8x)−8x+8y/64xy при x=√30, y=1/4.

Answer 1

1/8x−8x+8y/64xy=1/8x−8x+1/8х= 2/8х - 8х= 1/4х - 8х= (1-32х²)/4х
при x=√30 имеем: 
(1-32×30)/4√30= -959/4√30