Determine the unit rate of a marathon runner who travels 15/2 miles in 1/4 hour

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

Amovie streaming service charges it’s customers $15 a month. martina has $98 saved up. will she have any money left over if she pays for the maximum amount of months she can afford? explain.