Prime Factorization of 84

Express 84 as a product of its prime factors: $84 = 2 \times 2 \times 3 \times 7 = 2^2 \times 3^1 \times 7^1$.

$84 = 2^2 \times 3 \times 7$

Prime Factorization of 105

Express 105 as a product of its prime factors: $105 = 3 \times 5 \times 7 = 3^1 \times 5^1 \times 7^1$.

$105 = 3 \times 5 \times 7$

Prime Factorization of 140

Express 140 as a product of its prime factors: $140 = 2 \times 2 \times 5 \times 7 = 2^2 \times 5^1 \times 7^1$.

$140 = 2^2 \times 5 \times 7$

Calculate LCM

Take the highest power of each prime factor involved ($2^2, 3^1, 5^1, 7^1$) and multiply them together: $LCM = 2^2 \times 3 \times 5 \times 7 = 4 \times 3 \times 5 \times 7 = 420$.

$LCM = 4 \times 3 \times 5 \times 7 = 420$