54:18
91:13*4
60:15*9
70:14*8
(32-16)*4
(46-21)*3
(30-18)*7

54 /18 = 391 / 13 * 4 = 7 * 4 = 2860 / 15 * 9 = 4 * 9 = 3670 / 14 * 8 = 5 * 8 = 40(32 - 16) * 4 = 16 * 4 = 64(46 - 21) * 3 = 15 * 3 = 45(30 - 18) * 7 = 12 * 7 = 84 

54:18=391:13×4=2860:15×9=3670:4×8=40(32-16)*4=64(46-21)*3=75(30-18)*7=84