lika09836 7) 27/1000 x^15-27/200 x^10 y^2 +9/40 x^5 y^4-1/8 y^6

8) 27/125 x^12-27/50 x^8 y^3+9/20 x^4 y^6-1/8 y^9

9) 1/125 a^6+ 19683a^4/25^5+ 3^17 a^2/5^17+9^12/25^12