a. Let e represent the average problem-solving rate in problems per hour for Emily, and let a represent the average rate in problems per hour for Alejandro.
b. This is the equation for Monday. 3 hours times
e. problems per hour plus 1 hour times a problems per hour is equal to 139 problems.
c. 2e + 2a = 130
d. ii. Substitute the values in both equations to see if they satisfy the equations. Points i and ii satisfy the first equation. Point's ii and iii satisfy the second equation. The last point doesn't work in either equation. (e, a) = (37, 28).
e. Emily averages 37 problems per hour and Alejandro averages 28 problems per hour.