The definition of an inverse of a function is "the set of ordered pairs obtained by interchanging the first and second elements of each pair in the original function."
This means too find the inverse of a function using ordered pairs, switch the x- and y-coordinates.
This means that (-3, 9) goes to (9, -3); (-1, 1) goes to (1, -1); (0, 0) goes to (0, 0); and (2, 4) goes to (4, 2).
So, we know Carlos ran 21 miles per week, for 12 weeks....
That makes 21 mi/wk x 12 weeks = 252 miles.
Then we know each km is 0.621 mile.
So, we divide 252 miles by 0.621 mile/km to get= 405.80 km
Dividing miles by miles/km gives us the unit we want (km).
<u>There was a trap in this question,</u> because if instead of dividing the 252 miles by 0.621 you would have multiplied it, you would have gotten another answer listed... just not the right one. :-)