Okay well the starting is 28 dollars, right. But since there is a 20 percent discount, you have to turn 20% to a decimal. That means moving the decimal sign twice to the left to make it .20. From the it would be .20*28, that should equal 5.6. Now, that 5.6 is the amount you have to take away, it is the price of the sale. From then, you subtract which is 28-5.6 which should be 22.4. From that 22.4 you now take away two dollars and then it should be 22.4-2 which should be 20.4. Now that is your answer, 20.4.
The common factors for 28 and 42 are 1, 2, 7 and 14.
