Given x 2 - X - 1 = 0, find the value of x 3 - 2x + 1

Given x 2 - X - 1 = 0, find the value of x 3 - 2x + 1

∵x2-x-1=0,∴x3-2x+1=x(x2-x-1)+(x2-x-1)+2=0+0+2=2.