Question

what is the LCM of 15x,45y

Answer 1

Again reduce each term to prime factors: 15x is 3*5*x and 45y is 3*3*5*y so the LCD becomes 3*3*5*x*y LCD is 45xy

Answer 2

The LCD has the prime factors that are present in its product, when individual products have multiple prime factors you should use the maximum times it occurs in a tern, In the above 45 had 3 as a factor twice, therefore two 3s were used to obtain the LCD