Answer:
$4.5
Explanation:
We apply sales tax to the total cost, which in this case is $40 + $50 = $90.
Thus, we have 5% * $90 = $4.5
It even works individually if you apply the tax to both orders separately and add them together:
(50 * 5%) + (40 * 5%) = 4.5
2.5 + 2 = 4.5