What polynomial could you add to 3x^4-9x^3+5x^2-x+7 to get the sum of 3+4x^4+3x-x^3+3x^2?

Step-by-step explanation:

to find what you need to add, ur gonna have to subtract ... subtract the second polynomial from the first one

but lets rearrange the second one

4x^4 - x^3 + 3x^2 + 3 ... thats better

now, we subract

3x^4 - 9x^3 + 5x^2 - x + 7 - (4x^4 - x^3 + 3x^2 + 3) =

3x^4 - 9x^3 + 5x^2 - x + 7 - 4x^4 + x^3 - 3x^2 - 3) =

-x^4 - 8x^3 + 2x^2 - x + 4 <== = ur answer