2z2-21z+10

Factor -21 out of -21z.

2z2-21(z)+10

Rewrite -21 as -1 plus -20

2z2+(-1-20)z+10

Apply the distributive property.

2z2-1z-20z+10

2z2-1z-20z+10

Group the first two terms and the last two terms.

(2z2-1z)-20z+10

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

z(2z-1)-10(2z-1)

z(2z-1)-10(2z-1)

Factor the polynomial by factoring out the greatest common factor, 2z-1.

(2z-1)(z-10)

Factor 2z^2-21z+10