Calcule o valor das expressoes: a) (3/4)^2 x (2)^3 + (-1/2)^1 b) -2 x (3/2)^3 + 1^15 - (-2)^1 c) {(-5/3)^1 + (5/2)^-1}-1 d) (/2)^-3 x 0,5^-2 resolução!!!