Answer this question correctly for 24 points and

  $110

Step-by-step explanation:

Let a, b, and c represent the earnings of Alan, Bob, and Charles. The problem statement tells us ...

  a + b + c = 480 . . . . . . the combined total of their earnings

  -a + b = 40 . . . . . . . . . . Bob earned 40 more than Alan

  2a - c = 0 . . . . . . . . . . . Charles earned twice as much as Alan

Adding the first and third equations, we get ...

  (a + b + c) + (2a - c) = (480) + (0)

  3a + b = 480

Subtracting the second equation gives ...

  (3a +b) - (-a +b) = (480) -(40)

  4a = 440 . . . . . . . . simplify

  a = 110 . . . . . . . . . . divide by the coefficient of a

Alan earned $110.

Check

Bob earned $40 more, so $150. Charles earned twice as much, so $220.

The total is then $110 +150 +220 = $480 . . . . as required

h who knows

step-by-step explanation:

i hope this is what you were looking for.

see attached graph