Answer:
8428
Explanation:
hope you don't mind the writing...
when 172 is multiplied by 49 we first multiply 172 by 9 (red)
9*2=18 (8 at bottom 1 placed above the following number)
9*7 = 63 + 1 (that was carried form 18) = 64 (4 at bottom 6 placed above the following number)
9*1 =9 +6 (that was carried form 64)= 15 (because there's no other number following, 15 is placed as a whole at bottom)
we then multiply by 172 by 4, but before we do that we have to place a zero (blue) as a placeholder, its a rule, always.
same step were followed as above.
finally once getting both products from 9 and 4, you add them to get the product ( the answer of a multiplication problem) which is in purple
1548 + 6880 = 8428