Answer:
$$$$$$$$ the anwser is 4 i think thats how you solve it
Step-by-step explanation:
Answer:
The answer is 173,595
Step-by-step explanation:
Firstly, you multiply 815 by the first number of 213 which is 3
So:

Then 815 by the second number:

Then 815 by the third number:

Then you add all the numbers, but you have to put a zero to the right of the second product and two zeroes to the third product and so on..
In this case the addition is :
2445+8150+163000 = 173595
The number is 6860
The number 6 goes in both boxes
C. You'd be starting at a higher floor (positive number) and descending floors (negative number per x). If you assume x is time it's a little more logical and visual.