We have to rewrite the following fractions with fraction with least common denominator So LCD of the 2 fractions is going to be the LCM of both of these denominators over here. and if we can make this as common denominators we can add the two fractions First let us find the LCM, let me write it out LCD of 8 & 6 is going to be the LCM of 8 & 6 and a couple of ways to think about the LCM you could really take the multiples of 8 & 6 and see what their smallest common multiple is. Multiples of 6 - 6,12,18,24,30... i can keep going and the multiples of 8 are 8,16,24,. looks like we are done. I have found a common multiple it is the smallest multiple they have other common multiples like 48,72 and we can go on but this is their smallest common multiple So it is 24. Another way to find the LCM is take the prime factorization of 6 - 2x3 and the LCM of 6 must have one 2 & one 3 what is the prime factorization of 8 is 2x2x2. Inorder to be divisible by 8 we need to have three 2's in the prime factorization. To be divisible by 6 we need to have 2,3 and to be divisible by 8 we need three 2's, we have only one 2 so we add a couple more so thsi is now divisible by 6 & 8 So 2x2x2x3 = 24. So LCM of 8 & 6 which is the LCD also is 24 So we want to write each of this fractions as 24 as their denominator. So lets start with 2/8, i want to write that as / 24 so get the denominator as 24, we need to multiply the denominator by 3 inorder not to change the fraction, we need to multiply the numerator also by the same number so we will multiply numerator by 3 ; 2x3=6 so 2/8 = 6/24 2/8 x 3/3 = 6/24 and lets do the same things with 5/6 5/6 = / 24, i will do it in a different colour, blue to get the denominator from 6 to 24, we need to multiply by 4, so we need to multiply numerator also by 4 so 5x4 = 20 5/6 = 20/24 so we have written both the fractions with common denominator So we are done