Ta có: `x= 9 => x -9=0`
`Q(x) = x^14 - 10x^13 + 10x^12 -10x^11 +...+10x^2-10x +10`
`Q(x) =x^14 - (9+1)x^13 + (9+1)x^12 - (9+1)x^11 +...+ (9+1)x^2 -(9+1)x +10`
`Q(x)= x^14 - 9x^13 - x^13 + 9x^12 + x^12 -...+9x^2 + x^2- 9x - x +10`
`Q(x)= x^13(x -9) - x^12(x -9) +....+x(x-9) - x +10`
`Q(x)= x^13. 0 - x^12. 0 +...+ x. 0 - x +10`
`Q(x)= -x+10`
`=> Q(9) = -9+10`
`=> Q(9)= 1`
Vậy `Q(9) =1`