Question

using prime factorisation find HCF and lcm of 72,126,168 ​

Answer 1

72 = 2³ × 3²

126 = 2 × 3² × 7

168 = 2³ × 3 × 7

HCF = product of common terms with lowest power

==> HCF = 2 × 3

==> HCF = 6

LCM = product of prime factors with highest power

==> LCM = 2³ × 3² × 7

==> LCM = 504

Answer 2

HCF AND LCM OF 72 126 168

FACTORS  OF - 1)72 = 2*2*2*3*3

                          2)126 = 2*3*3*7

                          3)168 = 2*3*3*3*3

HCF = 2*3*3 = 18

LCM = 4536

Step-by-step explanation: