Resposta:

Olá bom dia!

Aqui segue algumas propriedades úteis da potenciação.

[tex]a^1 = a\\\\(-a)^b = a^b\ se\ b\ for\ par\\\\(-a)^b = -(a^b)\ se\ b\ for\ impar\\\\a^0 = 1\\\\0^b = 0\\\\a^b*a^c = a^{b+c}\\\\a^b:a^c = a^{b-c}\\\\(-1)^b = -1 \ se \ b \ for \ impar\\\\(-1)^b = +1 \ se \ b \ for \ par[/tex]

[tex]x = (-2)^4:4^2-4^2:(-2^3)\\\\x = 16:16 - 16:(-8)\\\\x = 1 - (-2)\\\\x = +3[/tex]

[tex]y = [(-1)^3-(-1)^5*(-1)^4] + (-1)^7[/tex]

y = [-1-(-1)*(1)] + (-1)

y = [-1-(-1)] - 1

y = [-1+1] - 1

y = 0 - 1

y = 0

Logo:

x * y =

= 3 * 0

= 0