Question

We know that according to the fundamental theorem of arithmetic, every composite number can be uniquely written as the product of its prime factors. But does a positive (+) sign make a difference for a number to be called a composite number.For example, 7 x 5 x 3 x 2 + 3. does the underlined make any difference in the no. to be called a composite no.? What if we use any other no. in place of 3 is it also a composite no.?

Answer 1

Hi!

Here is the answer to your question.

A number is called composite number if it has divisors other than 1 and itself. Numbers which are not prime are called composite numbers.

The given expression is 7 × 5 × 3 × 2 + 3.

7 × 5 × 3 × 2 + 3

= 3 (7 × 5 × 2 + 1) (Taking 3 as the common factor)

= 3 × (70 + 1)

= 3 × 71

So, the given expression represents a composite number.

Thus, the composite number is uniquely written as the product of the prime factors 3 and 71.

Cheers!