malik paid 480$ to purchase a certain number of pizzas, but 2 extra were delivered which decreased the amount per pizza by 1$. how many pizzas were delivered?
original number ---- x
origianal price per pizza = 480/x
actual number delivered ---- x+2
price per pizza = 480/(x+2)
480/x - 480/(x+2) = 1
multiply by x(x+2)
480(x+2) - 480x = x(x+2)
480x + 960 - 480x = x^2 + 2x
x^2 + 2x -960 = 0
(x+32)(x-30) = 0
x = 30 or a negative, which would make no sense
So the original order was 30, but they delivered 32
check:
480/30 = 16
480/32 = 15
price decreased by $1 ?? , YES