7.2×8－5x=3.657.6-5x=3.65x=57.6-3.65x=54x=10.8
7.2×8-5x=3.67.2×8-3.6=5x57.6-3.6=5x54=5xx=10.8
简化算法7.2*8-5x=3.65x=3.6*16-3.6 （7.2=3.6*2）5x=3.6*15x=3.6*3x=10.8
