Question

Tính nhanh : 

1/15 + 4/27 + 3/15 - 1/27

Answer 1

1/15+4/27+3/15-1/27

=(1/15+3/15)+(4/27-1/27)

=4/15+3/27

=.......

Answer 2

= 1/15+3/15+4/27-1/27

=4/15+4/27-1/27

=56/135 - 1/27 = 17/45

chúc bạn học tốt !

Answer 3

1/15 + 4/27 + 3/15 - 1/27 = 1/15 + 3/15 + 4/27 -1/27

                                        = 4/15 + 3/27

                                         = 17/45