Answer:
$54
Step-by-step explanation:
let the initial amount of money per person be x
let the total cost of the pizza be y
Before one person left:
10x = y ------------> (eq 1)
After one person left, each of the 9 remaining people had to pay $0.60 extra.
9(x+0.6) = y ----------(eq 2)
equating y from both equations
10x = 9(x+0.6)
10x = 9x+(0.6)(9)
10x = 9x + 5.4 (subtract 9x from both sides)
10x - 9x = 5.4
x = 5.4 (substitute this back into equation 1)
10x = y
y = 10(5.4) = $54