Question

If 4x = √5+ 2, then the value of x - 1/16x is

A) 1 B) -1 C) 4 D) 2√5

Answer 1

4x = √5+2

= x= √5+2/4

then,

x - 1/16x = (√5+2)/4 - 1/16×(√5+2)/4

= (√5+2)/4 - (√5+2)/16

= { 4(√5+2) - (√5+2)} /16

= { 3(√5+2)}/16

= ( 3√5 + 6 ) / 16