Đáp án:
f(x) – g(x)=x^7 – 3x^2 – x^5 + x^4 – x^2 + 2x – 7-(x – 2x^2 + x^4 – x^5 – x^7 – 4x^2 – 1)
=x^7 – 3x^2 – x^5 + x^4 – x^2 + 2x – 7-x +2x^2 - x^4 + x^5 + x^7 + 4x^2 +1
=(x^7+x^7)+(– 3x^2- x^2 +2x^2+ 4x^2 )+( – x^5 + x^5)+(x^4 - x^4)-8
=2x^7+2x^2-8
Vậy f(x) – g(x)=2x^7+2x^2-8