Question 300548
Can someone please solve the below and explain. Thank you so much. 
Factor Completly. Remember to look first for a common factor. Check by multiplying. If a polynomoal is prime state this. 3y^2-9y-84. Thanks again

3y^2 - 9y - 84 =

3*(y^2 - 3y - 28) =

3*(y - 7)*(y + 4)