hello..is this question correct?

find the derivative of F(x): x^9 + X^2 +1

using the power law i got: 9x^8 + 2x +1

now the derivative of a sum:

(derivative of 9x^8) + (derivative of 2x) + 1

answer:

72x^7+252x^6 y +504x^5 y^2 +630x^4 y^3 +504x^3 y^4 +252x^2 y^5 +72x y^6 +y^7 +3.

where y=delta X. as y approaches to 0.

final answer: 72x^7 +3

is it correct?? we dont know how to prove it with integration...we'll know it later...tks