1. Divide the leading term of the numerator (X^2) by the leading term of the denominator X to get the first term of the quotient: X.
2. Multiply X by (X - 4) to get X^2 - 4X.
3. Subtract (X^2 - 4X) from (X^2 - 4X + 1) to obtain the remainder: 1.
4. Since the degree of the remainder 1 is less than the degree of the denominator X - 4, we stop here.
The quotient is
X
Thus, the equation of the slant asymptote is
Y = X