Answer:
y^3 + 3^3
Step-by-step explanation:
1) Multiply each term of (y^2-3y+9) by y: y^3 - 3y^2 + 9y
2) Multiply each term of (y^2-3y+9) by 3: 3y^2 - 9y + 27
3) Add all of these terms together: y^3 + 27 = y^3 + 3^3
Note: this is an example of 'special products and factoring.'
