$\"\"$

The cost of a gallon of milk is m and the cost of a gallon of water is w.

The word $\"\"$ more than $\"\"$ represent the addition operation and its symbol is $\"\"$ .

The word $\"\"$ is $\"\"$ means that equal and its symbol is $\"\"$ .

The word $\"\"$ the cost of a gallon of milk m is 0.50 dollars more than five times the cost of a gallon of water is w $\"\"$ represent the equation $\"\"$ . $\"\"$

The equation is $\"\"$ .

Substitute the value of $\"\"$ in the original equation.

$\"\"$

Subtract 0.50 from each side.

$\"\"$

Divide each side by 5.

$\"\"$

Cancel common terms.

$\"\"$ . $\"\"$

The cost of a gallon of water is 0.65 dollars.