Question

Find a common prime factor in each of these pairs of numbers.

a) 21 and 411
b) 77 and 242
c) 56 and 63​

Answer 1

a) 3

b) 11

c) 7

Explanation:

The factors of 21 are: 1, 3, 7, 21

The factors of 411 are: 1, 3, 137, 411

A common prime factor is 3.

The factors of 77 are: 1, 7, 11, 77

The factors of 242 are: 1, 2, 11, 22, 121, 242

A common prime factor is 11.

The factors of 56 are: 1, 2, 4, 7, 8, 14, 28, 56

The factors of 63 are: 1, 3, 7, 9, 21, 63

A common prime factor is 7.

Answer 2

See below.

Explanation:

A) 3

B) 11

C) 7

-hope it helps