Question

1-5/6+7/12-9/20+11/30-13/4

Answer 1

应该是1-5/6+7/12-9/20+11/30-13/42

1-5/6+7/12-9/20+11/30-13/42

=1-(1/2+1/3)+(1/3+1/4)-(14+1/5)+(1/5+1/6)-(1/6+1/7)

=1-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7

=1-1/2-1/7

=5/14