simplifique as expressões númericos
a) (-2)2-2-1 b) 5-1+50-3-1 c) 3.10-2+5 d) 62-(-7)2
3-2+3-1
+1223 answers to a) to c) here: https://web2.0calc.com/questions/a-2-2-2-1-b-5-1-5-0-3-1-c-3-10-2-5#r1
\(D) \qquad \frac{6^2 - (-7)^2}{3^{-2} + 3^{-1}} = \frac{-13}{\frac{4}{9}}= \boxed{-\frac{117}{4}}\)
