Answer:
a=16
Explanation:
Given
(y-4)(y^2+4y+16)
To find the value of a in the resulting polynomial we have to solve the given expression
=y(y^2+4y+16)-4(y^2+4y+16)
= y^3+4y^2+16y-4y^2-16y-64
To find the value of a, both the polynomials will be compared
y^3+4y^2+16y-4y^2-16y-64
y^3+4y^2+ay-4y^2-ay-64
Comparing the coefficients of both polynomials gives us that
a=16
So, the value of a is 16 ..