13109660188,你好:
18×3/7+0.65×8/13-2/7×18+12/13÷1又7/13
=18×(3/7-2/7)+13/20×8/13+12/13×13/20
=18×1/7+13/20×(8/13+12/13)
=18/7+13/20×20/13
=2又4/7+1
=3又4/7
18*3/7+0.65*8/13-2/7*18+12/13÷1(7/13)
=18*3/7+0.4-18*2/7+12/13*13/20
=4/+18*1/7+6/10
=1+18/7
=25/7
12.22