Expert: Ahmed Salami - 4/3/2009

Question
if x^2 - 5x + 7 = 0, x^3 = ax + b, where a and b are integers. compute the ordered pair (a,b)?

Answer
Hi Carol,
If x^2 - 5x + 7 = 0
x^2 = 5x - 7
multiplying through by x
x^3 = 5x^2 - 7x
x^3 = (5x)x + (-7x)
comparing with
x^3 = ax + b
The ordered pair would be (5x, -7x) where x takes different values.
I hope i've understood your question correctly.

Regards