Value of X

[cartera]

284.If we know X^2 = X+1, what is X^ 3?

[spoiler]A: 2X+1[/spoiler]

[krisraam]

x^2 = x + 1

x^2 * x = x^3 = x(x+1)
==> x^2 + x
==> x+1 + x ( substitute x^2 = x+1)
==> 2x +1


Thanks
Raama