а) 16х^4-81y^4=(4x^2-9y^2)(4x^2+9y^2)=(2x-3y)(2x+3y)(4x^2+9y^2)
б)48a^4-3b^4=3(4a^2-b^2)(4a^2+b^2)=3(2a-b)(2a+b)((4a^2+b^2)
в)1/81m^8-1=(1/9m^4-1)(1/9m^4+1)=(1/3m^2-1)(1/3m^2+1)((1/9m^4+1=(1/V3 m-1)(1/V3 m+1)(1/3m^2+1)((1/9m^4+1)
г)32-1\2 m^6=1/2(64-m^6)=1/2(8-m^3)(8+m^3)=1/2(2-m)(4+2m+m^2)(2+m)(4-2m+m^2)
{xy=6
{2x-y=11
{y=2x-11
{x(2x-11)=6
x(2x-11)=6
2x²-11x-6=0
D=121+48=169=13²
x₁=(11+13)/4=6
x₂=(11-13)/4=-0.5
x=6⇒y=2*6-11=1
x=-0.5⇒y=2*(-0.5)-11=-12
Ответ: (6;1), (-0.5;-12)