Question

(1/15+3/49)*15-45/49能否简便?

Answer 1

(1/15+3/49)*15-45/49

=1/15×15+3/49×15-45/49

=1+45/49-45/49

=1

(1/15+3/49)*15-45/49

=(1/15+3/49)×15-3/49×15

=(1/15+3/49-3/49)×15

=1/15×15

=1