Answer:
-3/15 is the difference between 6/15-9/15
You first convert the 2 minutes and 30 seconds to 150 seconds.
Then, you take the 150s÷5m to get the number of seconds per mile.
The answer is 30s/m
Answer:
-1/3
Step-by-step explanation:
Slope is defined as "rise over run". If you count out the units, you should be able to see that your rise is 1 and your run is 3 and is pointing downward, so your answer is -1/3.
Alternatively you could use Slope Formula: 
Since they are similar, you need to find the ratio of similarity (I made up the term, there is probably a correct one that I can’t remember).
If you divide 16/40, you’ll find that that ratio is 2.5. So then you just multiply 16 x 2.5. You’ll get 18.
18 is the length of the top of the trapezoid.
You set 18=2x+4 and solve it algebraically. Subtract 4 from both sides.
14=2x
Divide by 2 and x=7
(You can also check that the ratio is right by 16/18 is the same decimal value as 40/45. You’ll get .88888...)