Answer
$(3z+1)(2z+1)$
Work Step by Step
First, for the polynomial $6z^2 + 5z + 1$, we write
$$
6z^2 + 5z + 1=6z^2 + 2z+3z + 1
.$$
By grouping the first two terms and the second two terms and then taking common factors, we have
$$
6z^2 + 2z+3z + 1=2z(3z+1)+(3z+1)=(3z+1)(2z+1)
.$$
