This is incorrect. In order to add two fractions that have unlike denominators, it is true that you first need to find a common denominator. When you change a fractions denominator you must also change it's numerator in proportion to the change in the denominator. For example, if you change the denominator in the fraction into a 4 then you are multiplying the denominator by 2, therefore you will also need to multiply the numerator by 2 which would give you a new fraction of