Respuesta :
(9x^4-13x^3-x-7)+(7x^3-2x+1)=
9x^4-13x^3-x-7+7x^3-2x+1=
9x^4+(-13+7)x^3+(-1-2)x-7+1=
9x^4+(-6)x^3+(-3)x-6=
9x^4-6x^3-3x-6
Answer: Option D.)9x^4−6x^3−3x−6
9x^4-13x^3-x-7+7x^3-2x+1=
9x^4+(-13+7)x^3+(-1-2)x-7+1=
9x^4+(-6)x^3+(-3)x-6=
9x^4-6x^3-3x-6
Answer: Option D.)9x^4−6x^3−3x−6
The answer to the question above is :
D.) 9x^4−6x^3−3x−6
Explanation: In adding polynomials, you have to directly add the similar terms. Always remember that you cannot add dissimilar terms. That is why the correct answer is letter D.