Question

Show the lcm of 21 38 36 45 by prime factorisation method

Answer 1

prime factors of these numbers are
$21 = 3 \times 7 \\ 38 = 2 \times 19 \\ 36 = 2 \times 2 \times 3 \times 3 \\ 45 = 3 \times 3 \times 5 \\ lcm = 2 \times 2 \times 3 \times 3 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \times 5 \times 7 \times 19 \\ lcm = 23940$

Answer 2

Hii friend!


21 = 3 × 7
38 = 2 × 19
36 = 2 × 2 × 3 × 3
45 = 3 × 3 × 5

LCM of 21 , 38 , 36 , 45 :-
= 2 × 2 × 3 × 3 × 5 × 7 × 19
= 23940