Ayuda con este limite

Lim (x^4 - 5x^3 + 9x^2 - 7x + 2) / (x^4 - 2x^3 + 2x^2 - 1)
x = 1

Use L'Hopital's rule
[4x^3-15x^2+18x-7]/[4x^3-6x^2+4x]
When x-->1
[4-15+18-7]/[4-6+4] = 0/2 = 0