Answer:
2 minutes
Step-by-step explanation:
The front of the train enters the tunnel and travels 1 km before the rear of the train enters the tunnel. Thus, the total distance traveled by the front of the train is 2 km, and this is covered in a certain number of hours:
Since distance = rate times time, time = distance / rate. In this particular case we have:
2 km
time = distance / rate = ------------------- = (1/30) hr
60 km/hr
(1/30) hr converts to 2 minutes, since 1 hr = 60 minutes
X*a = 244 is equation (1)
x+a = 2 is equation (2)
Solve equation (2) for 'a' to get
x+a = 2
a = 2-x
Call this equation (3)
We will plug equation (3) into equation (1)
x*a = 244
x*(a) = 244
x*(2-x) = 244
Notice how the 'a' is replaced with an expression in terms of x
Let's solve for x
x*(2-x) = 244
2x-x^2 = 244
x^2-2x+244 = 0
If we use the discriminant formula, d = b^2 - 4ac, then we find that...
d = b^2 - 4ac
d = (-2)^2 - 4*1*244
d = -972
indicating that there are no real number solutions to the equation x^2-2x+244 = 0
So this means that 'x' and 'a' in those two original equations are non real numbers. If you haven't learned about complex numbers yet, then the answer is simply "no solution". At this point you would stop here.
If you have learned about complex numbers, then the solution set is approximately
{x = 1 + 15.588i, a = 1 - 15.588i}
which can be found through the quadratic formula
Note: it's possible that there's a typo somewhere in the problem that your teacher gave you.
Answer:
yes, it's a function
Step-by-step explanation:
A function relates one input to one output, and it's "only" one output.
