来自姬光荣的问题
脱式计算.(能简算的要简算)7.69×2.1+2.1×1.31+2.118-(1.4+1.25×2.4)7.2÷1.6+0.8解方程:4×4.5-3X=6.33.
脱式计算.(能简算的要简算)
7.69×2.1+2.1×1.31+2.1
18-(1.4+1.25×2.4)
7.2÷1.6+0.8
解方程:4×4.5-3X=6.33.


脱式计算.(能简算的要简算)7.69×2.1+2.1×1.31+2.118-(1.4+1.25×2.4)7.2÷1.6+0.8解方程:4×4.5-3X=6.33.
脱式计算.(能简算的要简算)
7.69×2.1+2.1×1.31+2.1
18-(1.4+1.25×2.4)
7.2÷1.6+0.8
解方程:4×4.5-3X=6.33.
①7.69×2.1+2.1×1.31+2.1 =(7.69+1.31+1)×2.1 =10×2.1=21②18-(1.4+1.25×2.4)=18-(1.4+1.25×8×0.3)=18-[1.4+(1.25×8)×0.3]=18-[1.4+3]=18-4.4=13.6③7.2÷1.6+0.8=4.5+0.8=5.3 ...