Question

Factor out the greatest common factor
16y^5 - 24y^4 - 40y^3

Answer 1

What is the GCF of 16, 24 and 40?

Answer 2

8

Answer 3

Yes.

Answer 4

Take 8 out of the expression.

Answer 5

as a factor

Answer 6

So would it be 8y^3(2y^2-3y^2-5y)

Answer 7

Take out one more y

Answer 8

Where?

Answer 9

The GCF is 8y^3. You are correct.
Your mistake is that when you took out 8y^3, you left the wrong powers of y inside the parentheses for the second and third terms.