Multiply the price of the van by the sales tax:
26,857 x 0.06 = 1611.42
Add the sales tax and the cost of the fees to get the total cost:
26857 + 1611.42 + 250 = 28,718.42
Now multiply that by 20% and subtract from the total:
28,718.42 x 0.20 = 5743.68
28718.42 - 5743.68 = 22974.74
They are financing $22,974.74