Step-by-step explanation:
speed = distance/time
time = t = distance/speed
t = 180/b + (400-180)/c = 180/b + 220/c = 20(9/b + 11/c)
He started with 17 quarter's. He had a certain number of quarters he added to his collection each day, on day two he had 26, and two days later he had 35, meaning he increased the amount of quarters my 9 over two day's, so I subtracted 9 from 26 because if you do you can remove the quarters he added in from the ones he started with, so the answer is: He started with 17.
Simplify both sides of your equation.
Subtract 4 from both sides.
Multiply both sides by 2(-1).
m = -12
Make a change of coordinates:


The Jacobian for this transformation is

and has a determinant of

Note that we need to use the Jacobian in the other direction; that is, we've computed

but we need the Jacobian determinant for the reverse transformation (from

to

. To do this, notice that

we need to take the reciprocal of the Jacobian above.
The integral then changes to
