6) Factor: \( \quad y=16 a^{2} b^{6}+4 a^{4} b \)

To factor the expression \( y=16 a^{2} b^{6}+4 a^{4} b \), we start by identifying the greatest common factor (GCF). The GCF of the coefficients 16 and 4 is 4, and for the variables, we can take \( a^{2} \) and \( b \) as common factors. So we can rewrite the expression as: \[ y = 4a^{2}b(4b^{5} + a^{2}) \] Now, we have factored out \( 4a^{2}b \), leaving us with \( 4b^{5} + a^{2} \) inside the parentheses. That’s a clean factorization! Happy factoring!