English

Find three consecutive odd integers, the sum of whose squares is 83.

Advertisements
Advertisements

Question

Find three consecutive odd integers, the sum of whose squares is 83.

Sum
Advertisements

Solution

Let the three numbers be x, x + 2, x + 4
According to statements,
(x)2 + (x + 2)2 + (x + 4)2 = 83
⇒ x2 + x2 + 4x + 4 + x2 + 8x + 16 = 83
⇒ 3x2 + 12x + 20 = 83
⇒ 3x2 + 12x + 20 - 83 = 0
⇒ 3x2 + 12x - 63 = 0
⇒ x2 + 4x - 21 = 0
⇒ x2 + 7x - 3x - 21 = 0
⇒ x(x + 7) -3(x + 7) = 0
⇒ (x - 3)(x + 7) = 0
Either x - 3 = 0,
then x = 3
or
x + 7 = 0,
then x = -7
∴ Number will be 3, 3 + 2, 3 + 4 = 3, 5, 7
or
Numbers will be -7, -7 + 2, -7 + 4 = -7, -5. -3.

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 Mathematics [English] Class 10 ICSE
Chapter 5 Quadratic Equations in One Variable
Exercise 5.5 | Q 8.2
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×