Amy and Chang walk around a track. Any walks each lap in 9 minutes. Chang walks each lap in 12 minutes. The two of them begin at the the starting line at the same time. They walk until they meet up again at the starting line. How many laps did Amy complete.

They meet up when Amy complete her fourth lap

Step-by-step explanation:

Amy walk around a track one lap in 9 minutes

Chang walk around a track one lap in 12 minutes

The relation between 9 and 12 will give the answer to this question

36 is a minimum common multiple, since

36/9  =  4

And

36 /12 = 3

If Amy do the lap in 9 minutes, in 36 minutes she will do 4 laps

If Chang do the lap in 12 minutes, in 36 minutes will do 3 laps

Then They meet up again when Amy finished 4 laps

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!

its a straight line parallel to the time axis