题目
用递等式计算。① + ×( - )② ÷( + )× ③2- + ×0.25④0.1÷( - ÷0.75)⑤ -0.39÷(0.13×3.5)⑥ ×13+ ×25
答案:① 47+37×(12-16)=47+37×13=47+17=57②34÷(34+16)×16=34÷1112×16=34×1211×16=322③2-19+89×0.25=2-19+29=219④0.1÷(78-58÷0.75)=0.1÷(78-56)=110÷124=125⑤ 1012-0.39÷(0.13×3.5)=1012-0.39÷0.455=1012-67=9914⑥1784×13+1384×25=1384×17+1384×25=1384×(17+25)=1384×42=132