脱式计算：
（7.5+2.5）×0.25475÷25÷45.4÷18+12
999×1999+9992.25×1.8+17.5×0.18[1﹣（
+
）]×36．
25×0.4+1.69÷1.3 17.8×0.8+17.8×0.2 10.1×9.8．
能简算的用简便方法算．
2.5×3.4×0.48.24﹣2.68﹣1.326.5×2.3+6.5×6.7+6.5
7.8÷0.25÷41.37×992.5×32×1.25．
能简算的用简便方法算．
9.28+1.82÷0.7（71.2﹣71.2×0.9）÷0.256.5×2.3+6.5×6.7+6.5
7.8÷0.25÷41.37×99+1.374.8×6.2﹣12.4．
怎样算简便就怎样算．
（1）4.32+5.43+6.68（2）15.17﹣6.8﹣3.2（3）34.82﹣（4.82+15.2）
（4）15.27+4.72﹣5.28（5）4.02﹣3.5+0.98（6）5.8﹣4.5+5.8﹣4.5．
