修一条公路,开工3天修了1.5千米,照这样的速度,再修21天就可以完成任务,这条公路长多少千米?(用比例解)
计算,能简算的要简算. 3.2×1.8+2.54 198×0.51 1.25×32×2.5 0.8×72.4×12.5 5.2×10.1 2.5×3.7+6.3×2.5.
0.46×7.5+0.46×2.5.
脱式计算,能简便的要用简便方法计算. 0.36×1.5×0.40.05×3.2×4026×15.7+15.7×74 3.78×0.5﹣0.653.98+13.4×0.24(9.37+9.37+9.37+9.37)×2.5.
能简算的要用简便方法计算 24.1×1.5+7.59×15(3.7+17×0.4)÷3.575.36÷12﹣4.32×0.5 8.8×0.1257.6×5.3+3.7×7.66.6÷(0.68+0.42)
脱式计算.(能简算的要简算) (1)1.25×8.37×0.8(2)(9﹣2.35)×0.64(3)0.25×32×12.5 (4)0.15×1999+0.15(5)0.37×1.4﹣0.4×0.37(6)8.7×9.9.