Jan uses 22.5 gallons of water in the shower. This amount is 7.5 gallons less than what she uses when washing her clothes. Write and solve an equation to find out how many gallons she uses to wash her clothes.

22.5 (shower) = X (variable used in place of the amount of water she uses to wash clothes) - 7.5 (the amount she used in the shower is 7.5 gallons less than she uses for washing clothes)

22.5 = X - 7.5 " This is the equation.

Solve is by adding 7.5 to both sides to cancel out the negative 7.5 and you get (X = 30).