What is the slope of the line that passes through (1, 4) and (0,1)

How do i get the answer for 2/3 * 10/3

Florence price's brownies and more sells all types of cookies and pastries. on tuesdays, they markdown all brownies 75% to a sale of $1.50 a dozen. find the selling price and the markdown of a dozen brownies.

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup