1.

The sum of squares of two consecutive even natural numbers is 244; find the numbers.

Answer»

Let the first even natural number be x. 

∴ the next consecutive even natural number will be (x + 2). 

According to the given condition, 

x2 + (x + 2)2 = 244 

∴ x2 + x2 + 4x + 4 = 244 

∴ 2x2 + 4x + 4 – 244 = 0

∴ 2x2 + 4x – 240 = 0 

∴ x2 + 2x – 120 = 0 …[Dividing both sides by 2] 

∴ x2 + 12x – 10x – 120 = 0 

∴ x(x + 12) – 10 (x + 12) = 0 

∴ (x + 12) (x – 10) = 0

By using the property, if the product of two numbers is zero, then at least one of them is zero, we get 

∴ x + 12 = 0 or x – 10 = 0 

∴ x = -12 or x = 10 

But, natural number cannot be negative. 

∴ x = 10 and x + 2 = 10 + 2 = 12 

∴ The two consecutive even natural numbers are 10 and 12.



Discussion

No Comment Found