So, first we multiply the fraction by using the formula a/b times c/d= a times c/b times d
=(y^2-16) times 5y/2y(y-4)
Now, we cancel the common factor y
=(y^2-16) times 5/2(y-4)
Now, we factor 5(y^2-16)
We factor (y^2-16) first
y^2-16
Rewrite 16 as 4^2
y^2-4^2
Now, apply the formula x^2-y^2=(x+y)(x-y)
=y^2-4^2=(y+4)(y-4)
=5(y+4)(y-4)
=5(y+4)(y-4)/2(y-4)
Cancel the common factor y-4
=5(y+4)/2
Answer: 5(y+4)/2