$3, $1, $5, $2, $3, $9, $1 = $24 - $1 = $23 - $1 = $22.
$22 is the estimation of the bill when all of the amounts are rounded to the nearest dollar. The estimation is greater than the total bill which is 23 cents less than the estimation. The total on the register is reasonable and accurate.
(-1,1.5) because you add both ys and both xs then divide by two to find the middle
If he has 6 friends they will all get 8 cards
