8/9 × 15/28 × 21/25 = (8×15×21)/(9×28×25) = 2520/6300 = (2×1260)/(5×1260) = 2/5
Once, with three left over.
It is: 21+18+15 = 54 and 54/3 = 18 which is the mean average
315/21 = 15, hence 15 times 21 is 315
18
14/21 * 15/18 = 2/3 * 5/6 = 5/9
8/9 × 15/28 × 21/25 = (8×15×21)/(9×28×25) = 2520/6300 = (2×1260)/(5×1260) = 2/5
Once, with three left over.
It is: 21+18+15 = 54 and 54/3 = 18 which is the mean average
315/21 = 15, hence 15 times 21 is 315
(21/7) + (3 x 5) = 3 + 15 = 18
Hello there the answer to 18 over 21 or 18/21 is 6/7 or 6 over 7 . if you do not believe me check on your own . if you know your multiplication you would know that 18 and 21 have 3 in common so you multiply 18 and 21 times 3 and you get 6/7 . HOPE My answer helped you out ! Peace and deuces love you all . - Valentina Marilyn Tavares
18
19
It is (21+15)/2 = 36/2 = 18
18/21
this is a impossible question unless with decimals 2divied by 21= 2+9=18-21=3add a zero then times 15