1) a^3 + 27b^3= а^3+(3b)^3= (a+3b)*(a^2 - a*3b+(3b)^2)= (a+3b)*(a^2 - 3ab+27b^2)
2) m^3+n^3= (m+n)(m^2-mn+m^2)
3) x^6+y^6= (x^2)^3+(y^2)^3= ((x^2)+(y^2))*(x^2)^2 - x^2*y^2+(y^2)^2)
4) )k^6 + (pg)^6= (k^2)^3+(pg^2)^3= ((k^2)+(pg^2))*(k^2-k^2*pg^2+pg^2)