а)(8-m^2)(8+m^2)=64-m^4
б)(5y-y^2)(5y+y^2)=25y-x^4
в)(1+6n^2)(1-6n^2)=1-36n^4
г)-(0.2+7ab)(0.2-7ab)=-(0.04-49a²b²)=47a²b²-0.04
а)(8-m^2)(8+m^2)=64-m^4
б)(5y-y^2)(5y+y^2)=25y-x^4
в)(1+6n^2)(1-6n^2)=1-36n^4
г)-(0.2+7ab)(0.2-7ab)=-(0.04-49a²b²)=47a²b²-0.04