English

There are three consecutive positive integers such that the sum of the square of the first and the product of other two is 154. What are the integers? - Mathematics

Advertisements
Advertisements

Question

There are three consecutive positive integers such that the sum of the square of the first and the product of other two is 154. What are the integers?

Sum

Solution

Let the first integer = x
then second integer = x + 1
and third integer = x + 2
Now according to the condition,
x2 + (x + 1)(x + 2) = 154
⇒ x2 + x2 + 3x + 2 - 154 = 0
⇒ 2x2 + 3x - 152 = 0
⇒ 2x2 + 19x - 16x - 152 = 0
⇒ x(2x + 19) - 8(2x + 19) = 0
⇒ (2x + 19)(x - 8) = 0
Either 2x + 19 = 0,
then 2x = -19

⇒ x = `-(19)/(2)`
But it is not possible as it is not an positive integer.
or
x - 8 = 0,
then x = 8
∴ Numbers are 8, (8 + 1) - 9 and (8 + 2) = 10.

shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Quadratic Equations in One Variable - Exercise 5.5

APPEARS IN

ML Aggarwal Understanding ICSE Mathematics [English] Class 10
Chapter 5 Quadratic Equations in One Variable
Exercise 5.5 | Q 7
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×