Answer:
mud
Step-by-step explanation:
Answer:
16
Step-by-step explanation:
x + 3= 9
x = 6
2x + 4= 2*6 + 4
2x + 4 = 12 + 4
2x + 4 =16
Charlies 16
hope it helps
Let
x--------> the time in hours
y-------> the distance in miles
we know that
The speed is equal to

in this problem


<u>Equation First Train</u>

<u>Equation Second Train</u>

---------> equation 
Substitute the values of
and
in the equation 

Solve for x


therefore
<u>the answer is</u>

The Jacobian for this transformation is

with determinant
, hence the area element becomes

Then the integral becomes

where
is the unit circle,

so that

Now you could evaluate the integral as-is, but it's really much easier to do if we convert to polar coordinates.

Then
