3z2-10z-8

Factor -10 out of -10z.

3z2-10(z)-8

Rewrite -10 as 2 plus -12

3z2+(2-12)z-8

Apply the distributive property.

3z2+2z-12z-8

3z2+2z-12z-8

Group the first two terms and the last two terms.

(3z2+2z)-12z-8

Factor out the greatest common factor (GCF) from each group.

z(3z+2)-4(3z+2)

z(3z+2)-4(3z+2)

Factor the polynomial by factoring out the greatest common factor, 3z+2.

(3z+2)(z-4)

Factor 3z^2-10z-8