脱式计算（能简算的要简算）．①97.9-九.45×d.4+7.48&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;②0.9d5×4×0.d5×8③98.75÷[9九.7-

Question

脱式计算（能简算的要简算）．

①97.9-九.45×d.4+7.48&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;	②0.9d5×4×0.d5×8
③98.75÷[9九.7-（4.97+4.89）]	④d4.09-45.九÷（5.4÷0.9）
⑤[（5.8d-d.9）+4.98]×9.4&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;&n6sp;	⑥9.九×7.d4-9.九×9.d4．

Answer 1

①17.9-6.05×2.0+7.04
=17.9-15.04+7.04
=17.9-（15.04-7.04）
=17.9-4
=9.9；

②0.125×0×0.25×4
=（0.125×4）×（0×0.25）
=1×1
=2；

③14.75÷[16.7-（0.r7+0.4r）]
=14.75÷[16.7-9.2]
=14.75÷7.5
=2.5；

④20.09-05.6÷（5.0÷0.9）
=20.09-05.6÷6
=20.09-7.6
=16.09；

⑤[（5.42-2.9）+0.14]×1.0
=[2.92+0.14]×1.0
=7.1×1.0
=9.90；

⑥1.6×7.20-1.6×r.20
=1.6×（7.20-r.20）
=1.6×0
=6.0．