GCF= 2
LCM=180
Step by step for GCF=
The prime factorization of 20 is 2,5
The prime factorization of 18 is 2,3
The common multiple they share is 2
Step by step for LCM=
the prime factorization of 18
18 = 2 × 3 × 3
the prime factorization of 20
20 = 2 × 2 × 5
Multiply each factor the greater number of times it occurs to find lcm
LCM = 2 × 2 × 3 × 3 × 5
LCM = 180