1. m^2-81=(m+9)*(m-9)
2. b^2-121c^2= (b-11с)*(b+11с)
3. 169m^2-16n^2= (13m-4n)*(13m+4n)
4. 36m^4-k^2p^2=(6m^2-kp)*(6m^2+kp)
5. (a+3)^2-144=(а+3-12)*(а+3+12)
6. p^3-t^3=(p-t)*(p^2+рt+t^2)
7. 27-p^3=(3-р)*(9+3р+р^2)
8. 8t^3+1=(2t+1)*(4t^2-2t+1)
9. 8p^3+125t^3=(2p+5t)*(4p^2-10pt+25t^2)
10. c^2-2cm+m^2= (c-m)^2
11. 9+6c+c^2= (3+c)^2
12. 81c^2-36cm+4m^2= (9c-2m)^2
13. 25c^2+10cm^2+m^4= (5c+m^2)^2