Basically, the inputs are the x values on the table. Plug those into the function. "Multiply the input by -1/2, then add 3" translates to -1/2(x) + 3.
If you would like me to actually put the answers down, then I'll put them in the comments after you request them.
1 3/4 hours of work equates to $18.375 so $18.38.
2 1/3 hours of work equates to $24.50.
1 5/12 hours of work equates to $14.875 so $14.88
Add all values $18.38+$24.50+$14.88 = $57.76
Doug has a total amount of earnings which = $57.76, good luck!
(x-2) + (x-1) + x + (x+1) + (x-2) + (x+3) = 447
6x + 3 = 447
6x = 447 - 3
6x = 444
x = 444/6
x = 74
Since we know the value for c and d we just plug them into the equation which will look like this. 6•5^2-5•4+8
Answer: 138