What is the Least Common Multiple of 70 and 77?
Least common multiple or lowest common denominator (lcd) can be calculated in two way; with the LCM formula calculation of greatest common factor (GCF), or multiplying the prime factors with the highest exponent factor.
Least common multiple (LCM) of 70 and 77 is 770.
LCM(70,77) = 770
Least Common Multiple of 70 and 77 with GCF Formula
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 70 and 77, than apply into the LCM equation.
GCF(70,77) = 7
LCM(70,77) = ( 70 × 77) / 7
LCM(70,77) = 5390 / 7
LCM(70,77) = 770
Least Common Multiple (LCM) of 70 and 77 with Primes
Least common multiple can be found by multiplying the highest exponent prime factors of 70 and 77. First we will calculate the prime factors of 70 and 77.
Prime Factorization of 70
Prime factors of 70 are 2, 5, 7. Prime factorization of 70 in exponential form is:
70 = 21 × 51 × 71
Prime Factorization of 77
Prime factors of 77 are 7, 11. Prime factorization of 77 in exponential form is:
77 = 71 × 111
Now multiplying the highest exponent prime factors to calculate the LCM of 70 and 77.
LCM(70,77) = 21 × 51 × 71 × 111
LCM(70,77) = 770