3.2乘0.48加0.48乘4.9加8.1乘0.52的简便运算=（3.2+4.9）x0.48+8.1x0.52=8.1x0.48+8.1x0.52=8.1x(0.48+0.52)=8.1x1=8.1
48.4÷0.8×1.2的简便运算怎么写解：原式=60.5x1.2 =60.5x（1+0.2） =60.5x1+60.5x0.2 =60.5+12.1 =72.6
