Alana bought a stock, which dropped 10% from the previous day. the total cost of her stock, with the price drop, was $253.10. which equation could she use to find the price of the stock before the price drop? a.)z=253.10+0.10 b.)0.10z=253.10 c.)z+0.10(z)=253.10 d.)z-0.10(z)=253.10

The price of the stoke is denoted with Z.
Alana's total cost with the price dropped included is $253.10. This means that we can write the equation:
total cost with the price drooped=price of the stock before the price dropped - the dropped price

$253.10=Z-0.10(Z)

or, rewritten:

D.)z-0.10(z)=253.10