Use the pythagorean theorem to find the distance between the points (4,3) and (-4,-3)

Draw a right triangle (attachment below):

Length of the vertical line = 6 units

Length of horizontal line = 8 units

a^2 + b^2 = c^2

6^2 + 8^2 = 100

Square root of 100 = 10

The distance between the two points is 10 units.

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