8.1×1.3-8×1.3+1.9×1.3+11.9÷1.36[(7.6-5.2)÷0.4+2.54]×32
递等式计算.30﹣1.6÷ +÷6 ×(+)(+)÷ (0.75﹣)×(+)
解方程或解比例.x﹣x=10; 0.6:x=:2.
直接写出得数.4π= ×= ÷= ×0.8=0.75+= ÷= 1÷25%= 0÷=0.52= ÷= 5÷= 2﹣=
计算下面各题,能简算的要简算.75﹣15.38+61.25﹣4.62 765×64×0.5×2.5×0.12550×96+57×4+7×66 0.0495×2500+495×0.24+51×4.95
解方程:9×1.8﹣12x=1.8(x﹣5)=0.45.6÷(70%x)=5%