3a to the power of 2 plus 5a minus 2
The answer is -8 (-8=2*-4)
Answer:
Problem 1) frequency: 160 heartbeats per minute, period= 0.00625 minutes (or 0.375 seconds)
Problem 2) Runner B has the smallest period
Problem 3) The sound propagates faster via a solid than via air, then the sound of the train will arrive faster via the rails.
Step-by-step explanation:
The frequency of the football player is 160 heartbeats per minute.
The period is (using the equation you showed above):

second problem:
Runner A does 200 loops in 60 minutes so his frequency is:
loops per minute
then the period is: 0.3 minutes (does one loop in 0.3 minutes)
the other runner does 200 loops in 65 minutes, so his frequency is:
loops per minute
then the period is:

Therefore runner B has the smaller period
Answer:
B
Step-by-step explanation:
edge 2020
2.8. The mean of the problem was 10. After subtracting each number by 10 I added the absolute value of each difference. I divided that sum by 5 and got 2.8