Equation: $59.50 - $30.00 = $0.25X =$29.50 = $0.25X =$29.50/$0.25 = X = 118 text messages used Explanation - First you take the total bill less the monthly fee of $30 to get $29.50. This amount represents the amount of the bill generated by the text messages you used. Then you divide this amount by $0.25 to get the total number of text, which is 118.