Respostas

2014-03-06T19:59:32-03:00
(-3)² = (-3)*(-3) = +9
-3² = -(+3)*(+3) = -(+9) = -9
 x^{-1} =  \frac{1}{x}\\\\
x^{-2} =  \frac{1}{x^{2}}