7.2乘0.2加2.4乘1.4 解：采用分配律，原式=7.2x0.2+2.4x1.4=7.2x0.2+0.2x16.8=0.2x（7.2+16.8）=0.2x24=4.8
如图
7.2×0.2+2.4×1.4=8×0.9×0.2+8×0.3×1.4=8×（0.18+0.42）=8×0.6=4.8
