Ezra uses his bank card to buy gasoline for his car three times. Each time he buys gasoline, it costs $180.50. He then deposits $50 in his bank account. What is the change in his bank account balance in dollars as a result of these transactions

The price of gasoline each time of $180.50 is excessive so this might be a typo. I will answer with that figure and then with the figure I think is right.

Using gasoline price of $180.50;

Change in bank account = 50 - (180.50 * 3)

= -$491.50

Using gasoline price of $18.50.

Change in bank account = 50 - (18.50 * 3)

= -$5.50

change of stock price/initial stock price on friday * total stock value = change of stock value

0.89/73.73 *x = 42.72

x=3539.04 = total stock value at initial stock price on friday .

total stock value at initial stock price on friday/ initial stock price on friday = number of shares

3539.04/73.73 = 48 shares

they own 48 shares of this stock