Question

简便运算(3-9/8+8/9)*21/13-169/56=?

Answer 1

=[3-(1+1/8)+(1-1/9)]x21/13-(13/7-13/8)/13

=[(3-1/8-1/9)x21-13/7+13/8]/13

=(63-21/8-3/7-13/7+13/8)/13

=(63-1-16/7)/13

=(60-2/7)/13

=418/91