Answer:

-8x² +7xy +y⁵

Step-by-step explanation:

x³ - 9x²y + 7xy² + y⁵

If the term doesn't have a coefficient,it is considered that the coefficient is 1.

1x²-9x²+ 7xy² +y⁵

Collect like terms by subtracting their coefficient

(1-9)x²+7xy²+ y⁵

Calculate the difference

-8x² +7xy +y⁵