we assume that "x-1/x" should be correctly written as "(x-1)/x"

we also assume that "x^4+1/x^4" should be correctly written as "(x^4+1)/x^4 "

(x-1)/x = 3

3x = x-1

2x = -1

x = -1/2

we substitute '-1/2' for 'x' in the final expression, (x^4+1)/x^4:

((-1/2)^4 + 1)/(-1/2)^4 = 17

if (x-1)/x =3, then (x^4+1)/x^4 is equal to 17