S=d/t ⇒d=s*t
s=speed
d=distance
t=time
The first train :
d=x
x=70 miles/h*t ⇒ x=70t (1)
The second train
d=360 miles - x
360 miles - x=80 miles/h*t ⇒360-x=80t ⇒ x=360-80t (2)
therefore, with the equations (1) and (2) we have a systeme of equations:
x=70t
x=360-80t
we can solve this system of equations by equalization method.
70t=360-80t
70t+80t=360
150t=360
t=360/150=2.4 (≈2 hour 24 minutes)
Answer: the first train meet with the second train in 2 hour 24 minutes.
Answer:
0.012t + 28 = 30
Step-by-step explanation:
The depth starts at 28 meters. The amount of increase in t minutes will be 0.012t, so the total depth after t minutes is ...
0.012t +28
We want to find when that is equal to 30, so the appropriate equation is ...
0.012t +28 = 30
Answer:

Step-by-step explanation:
We are given that Ben has a cell phone plan that provides 200 free minutes each month for a flat rate of $39.
We are also told that For any minutes over 200, Ben is charged $0.35 per minute.
let x be the minutes used each month
So, if 
So, coat will be $39
If 
So, Ben is charged $0.35 per minute
So, when 
So, charge = 
So, the piecewise functions accurately represents charges based on Ben's cell phone :

Answer:
A
Step-by-step explanation:
A is the correct answer. A coefficient is just a number that appears in front of a variable. Please note that a number that doesn't have a variable behind it is still a coefficient since there is technically a variable behind it with a power of 0.