Joe walked 4/9 mile in 4/5 of an hour what is his unit per mile

(4/9) mile in (4/5) hr

we want x mile in (5/5) hr

Set up a proportion.

(4/9) / (4/5) = x / (5/5)

(4/5) x = (4/9) (5/5)

(4/9) x = (4/5) (5/5)

(4/9) x = (4/5)

Multiply both sides by (9/4) to clear the fraction

x = (4/5) (9/4)

x = 9/5 hr per mile

Find common denominators and move from there