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

54 /18 = 3
91 / 13 * 4 = 7 * 4 = 28
60 / 15 * 9 = 4 * 9 = 36
70 / 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=3
91:13×4=28
60:15×9=36
70:4×8=40
(32-16)*4=64
(46-21)*3=75
(30-18)*7=84