Answer:
Step-by-step explanation:
Given : 
Solution :
Part A:
First find the potential roots of p(x) using rational root theorem;
So, 
Since constant term = -60
Leading coefficient = 1
Thus the possible roots are 
Thus from the given options the correct answers are -10,-5,3,15
Now For Part B we will use synthetic division
Out of the possible roots we will use the root which gives remainder 0 in synthetic division :
Since we can see in the figure With -5 we are getting 0 remainder.
Refer the attached figure
We have completed the table and have obtained the following resulting coefficients: 1 , 1,−12,0. All the coefficients except the last one are the coefficients of the quotient, the last coefficient is the remainder.
Thus the quotient is 
And remainder is 0 .
So to get the other two factors of the given polynomial we will solve the quotient by middle term splitting
Thus x-3 and x+4 are the other two factors
So , p(x)=(x+5)(x-3)(x+4)
