PLEASEEE HELP

1. Andrea ran and biked for a total of 32 mi in 4 hours. Her average running speed was 5 mph and her average biking speed was 13 mph.
Let x = total hours Andrea ran.
Let y = total hours Andrea biked.
Use substitution to solve for x and y. Show your work. Check your solution.
(a) How many hours did Andrea run?
(b) How many hours did she bike?