怎样简便就怎样计算56.73×259﹣56.73×159; (﹣)×11×12;138×1+23.3×(2﹣75%)﹣125%×38+(1+0.25)×28.7; +.
9-4= 9-5= 4+5=
10-4= 10-6= 4+6=
5+2= 7-5= 7-2=
4+1= 5-1= 5-4=
2+6= 8-6= 3+3= 6-3=