How can i show that a * b = a+b+ab/100 is commutative?

Why is it so easy to buy on impulse and overspend with a credit card? what could you do to counteract this tendency?

Carlos by 24 mi and ran 6 miles what is the ratio of the distance carlos ran to the distance he biked

You are living in aldine, tx and you are planning a trip to six flags in arlington, tx. you look on a map that has a scale of 0.5 inches to 30 miles. if the map shows the scale distance from aldine to arlington is 4 inches, how far is the actual distance?