What is the LCM of 45 and 66?

Answer 1

the LCM of two numbers times the greatest common divisor of those two numbers is the product of those two numbers

LCM(45 and 66) * GCD(45 and 66) = 45*66

To find the GCD, factor the two numbers

45 = 9*5 = 3*3*5 = 32 * 5

66 = 6*11 = 2 * 3 * 11

The greatest common divisor is 3 since 45 isn't divisible by 2 or 11 and 55 isn't divisible by 32 or 5 but both are divisible by 3.

LCM * 3 = 2970 Plugging into the above formula

LCM = 2970 /3 = 990