Question

find lcm using prime factorization of 28 15,42​

Answer 1

Answer:

$a = 28 = 2 \times 2 \times 7 = {2}^{2} \times 7 \\ b = 15 = 3 \times 5 \\ c = 42 = 2 \times 3 \times 7 \\ here \: hcf \: is \: 1 \\ now \: lcm \: of \: a \: and \: b \: = \frac{28 \times 15}{1} = 420 = d \\ now \: lcm \: of \: c \: and \: d = \frac{42\times 420}{1} = 17640$

Answer 2

Answer :

The answer is420