Question

4. Solve the following problems using HCF.
(a) Find the biggest number that divides 84 and 126 without leaving a remainder.​

Answer 1

Answer:

Step 1 : Find the prime factors of the given numbers by prime factorisation method

2 | 84

2 | 42

3 | 21

7 | 7

| 1

3 | 126

3 | 63

3 | 21

7 | 7

| 1

84 = 2 × 2 × 3 × 7

126 = 3 × 3 × 3 × 7

Step 2 : Find the common factors and HCF

Common factors = 3 × 7

= 21

∴ HCF = 21

∴ The biggest number that divide 84 and 126 without leaving a remainder is \bold{21}21