Question

Find the consecutive natural nos whose product is20

Answer 1

Answer:5,4

Step-by-step explanation:

Let the first number is x , so another number = ( x + 1 ).

A/Q,

Product of 2 consecutive natural numbers = 20

⇒ x ( x + 1 ) = 20

⇒ x² + x = 20

⇒ x² + x - 20 = 0

⇒ x² + 5x - 4x - 20 = 0

⇒ x ( x + 5 ) - 4 ( x + 5 ) = 0

⇒ ( x + 5 ) ( x - 4 ) = 0      

⇒ ( x + 5 ) = 0 ÷ ( x - 4 )    ⇒ ( x - 4 ) = 0 ÷ ( x + 5  )

⇒ ( x + 5 ) = 0                    ⇒ ( x - 4 ) = 0

∴  x = -5.                            ∴  x = 4

So, x = 4 or -5 but it is given that x is a natural number and -5 is not a natural number as it is a negative number.

Therefore, x = 4.

First number = x = 4

Second number = ( x + 1 ) = 4 + 1 = 5

The required numbers are 4 and 5.