Answer:
x = 15
y = 63
Step-by-step explanation:
9x - 7 + 4x - 8 = 180
13x = 195
x = 15
9x - 7 = 2y + 2
126 = 2y
y = 63
Answer:

Step-by-step explanation:
The last one is also the answer
Using the rational exponet rule,
![\sqrt[n]{ {x}^{m} } = x {}^{ \frac{m}{n} }](https://tex.z-dn.net/?f=%20%5Csqrt%5Bn%5D%7B%20%7Bx%7D%5E%7Bm%7D%20%7D%20%20%3D%20x%20%7B%7D%5E%7B%20%5Cfrac%7Bm%7D%7Bn%7D%20%7D%20)
Using this number,

40 is the base so it will stay same. Remember this is a square root sign so our nth root is 2 so our denominator if the rational exponet is 2.

so our numerator is 1 so

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:
128
Step-by-step explanation:
The answer will be (2) 0 and 9
X^2(x-9)
X=0, and 9