Answer:
$10.50
Explanation:
If you draw the points on a grid, you will see that the length of the rectangle is 8 -2 = 6 feet & width of the rectangle is 5 -3 = 2 feet.
Hence the area of the rectangle is 6 * 2 = 12 feet^2
Since one bag cover 6 ft^2, he will need 2 bags to cover 12 ft^2.
Each bag costs 5.25, so 2 bags will cost 5.25 * 2 = $10.50
Gardner will need $10.50 to cover the garden