Resposta:
7)
[tex]x = - 4 \\ y = 2 \\ \\20 {x}^{3} + 2 {x}^{2} {y}^{5} \\ \\ 20 {( - 4)}^{3} + 2( { - 4)}^{2} (2) {}^{5} \\ \\ 20( - 64) + 2(16)(32) \\ \\ - 1280 + 1024 \\ \\ \blue{ - 256}[/tex]
8)
[tex]( {3}^{6} \times {3}^{ - 2} ) \div ( {3}^{4} ) \\ \\ ( {3}^{6 + ( - 2)} ) \div ( {3}^{4} ) \\ \\ ( {3}^{4} ) \div ( {3}^{4} ) \\ \\ {3}^{4 - 4} \\ \\ {3}^{0} \\ \\ \blue{ 1}[/tex]
Bons Estudos!
