If you would like to write each rate as a unit rate, you can do this using the following steps:
$2 ... 5 cans of a soup
$1 ... x cans of a soup = ?
2 * x = 5 * 1
2 * x = 5
x = 5 / 2
x = 2.5 cans of a soup per $1
$2 ... 5 cans of a soup
$x = ? ... 1 can of a soup
2 * 1 = 5 * x
2 = 5 * x
x = 2 / 5
x = $0.4 per 1 can of a soup
