9.4×2.8+5.6×0.3用简便方法9.4×2.8+5.6×0.3=9.4×2.8+2.8×2×0.3=9.4×2.8+2.8×0.6=(9.4+0.6)×2.8=10×2.8=28
9.4×2.8+5.6×0.3用简便方法做,要提取公因式2.89.4×2.8+5.6×0.3=2.8(9.4+2*0.3)=2.8*10=28
命题9.4×2.8+5.6×0.3=0.7(9.4*4+8*0.3)=0.7*(37.6+2.4)=0.7*40=28