step-by-step explanation:
4227473658779875563886538705958641728563470543621287463824132573847969p05749365273847906970680574936214
$25
25 - 4.50 = 20.5
20.5 / 2 = 10.25
10.25 + 10 = 20.25
20.25 - 12.50 = 7.75
therefore the answer is $25 as shown as the first number.