1) (-4,2)² = (- 42/10)² = 1764/100 = 441/25 = 17,64
2) (-0,8)³ = (- 8/10)³ = - 512/1000 = - 0,512
[tex](-4,2)^2=(-4,2)\cdot (-4,2)=+17,64\\\\\\(-0,8)^3=(-0,8)\cdot (-0,8)\cdot (-0,8)=-0,512[/tex]