The baldwin family walked four over five of a mile in four over nine of an hour. what is their unit rate in miles per hour?

So walked 4/5 mile in a 4/9 h  so just use the rule of 3 simple 

60 minutes 1 hour
x min. 4/9 h

x = 4/9 *60/1 = 240/9 =  26,6 min. 

4/5 mile in 26,6 min.
1 mile   x min.

x = 1*26,6/(4/5) = 26,6 /(0,8) = 33,25 min. 

1 mile 33,25 min.
x miles 60 min.

 x = 60/33,25 = 1,8 miles 

so their unit rate in miles per hour will be 1,8 miles / hour 

hope this will help you 

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats