Respostas

2013-12-16T13:19:52-02:00
-2/9 . (1/4+1/5)           mmc de 4,5 = 20
-2/9 . (5/20 + 4/20)
-2/9 . (9/20)
-2/9 . 9/20
-18/180
-1/10

(-5)² . (-6)
25 . -6
-150

1-(1/2)².1/5+2/25+1/5)
1-(1/4 . 1/5 + 2/25 + 1/5)               
1-(1/20 + 2/25 + 1/5 )            mmc de 20,25,5 = 100
1-(5/100 + 8/100 + 20/100)
1-(33/100)
1-33/100                      mmc de 1,100 = 100
100/100 - 33/100
67/100