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The sum of the Squares of three consecutive number is 110.
Then determine the Three Numbers.​

User Jim Harte
by
2.5k points

2 Answers

14 votes
14 votes

Answer:

  • ± (5, 6, 7)

Explanation:

Let the three consecutive numbers be denoted as :

  1. x
  2. x + 1
  3. x + 2

Identity

  • (x + a)² = x² + 2ax + a²

It is given that the sum of the squares of these numbers add up to 110.

  • (x)² + (x + 1)² + (x + 2)² = 110
  • x² + x² + 2x + 1 + x² + 4x + 4 = 110
  • 3x² + 6x + 5 = 110
  • 3x² + 6x - 105 = 0
  • x² + 2x - 35 = 0
  • x² + 7x - 5x - 35 = 0
  • x(x + 7) - 5(x + 7) = 0
  • (x - 5)(x + 7) = 0
  • x = 5 or x = -7

Taking x = 5

  • x² = 5² = 25
  • (x + 1)² = 6² = 36
  • (x + 2)² = 7² = 49
  • 25 + 36 + 49 = 110

Taking x = -7

  • x² = (-7)² = 49
  • (x + 1)² = (-6)² = 36
  • (x + 1)² = (-5)² = 25
  • 49 + 36 + 25 = 110

Solution

  • 5, 6, 7 ⇔ -7, -6, -5
  • ± (5, 6, 7)
User Abbasov Alexander
by
3.0k points
22 votes
22 votes


\large\bold{{Question :-}}The sum of the Squares of three consecutive number is 110. Then determine the Three Numbers.


\large\bold\red{\underline{Answer :-}}

So, First of all The Question is to find out three consecutive Numbers .

First of all let's learn a little about Consecutive Numbers. So, Consecutive Numbers are the Numbers which follows each other. For example :- 1,2,3,4 are consecutive Numbers.

Let's start with Our Question :-

  • Let The First consecutive number be = x
  • and second number be = x + 1
  • Third number be = x + 2

So,


:\pink\implies
\bold{{(x)^(2)}} +
\bold{{(x + 1)^(2)}} +
\bold{{(x + 2)^(2)}} =
\bold{{110}}


:\pink\implies
\bold{{(x)^(2)}} +
\bold{{(x)^(2)}} +
\bold{{(1)^(2)}}+
\bold{{2x}} +
\bold{{(x)^(2)}} +
\bold{{(4)}}+
\bold{{(4x)}} =
\bold{{110}}


:\pink\implies
\bold{{3x^(2)}} +
\large\bold{{6x}} +
\bold{{5}} -
\large\bold{{110}} =
\bold{{0}}


:\pink\implies
\bold{{3x^(2)}} +
\bold{{6x}} -
\bold{{105}} =
\bold{{0}}

By taking 3 Out as Common, we are left with the Quadratic Equation :


:\pink\implies
\large\bold{{1x^(2)}}+
\large\bold{{2x}} -
\large\bold{{35}} =
\large\bold{{0}}

By Using Quadratic Formula,

x = -b ± √(b)^2— 4 × a × c / 2a

x = -2 ± √(2)^2— 4 × 1 × -35 / 2×1

x = -2 ± √144/2

[ As we know that "144" is square of 12 ]

x = -2 ± 12/2

  • Taking Positive
  • x = -2+12/2
  • x = 5

Hence, x = +5

x +1 = 5+1 = +6

x+2 = 5+2 = +7

  • Taking Negative sign
  • x = -2-12/2
  • x = -7

Hence, x = -7

x+1 = -7+1 = -6

x+2 = -7+2 = -5

Hence, The Three consecutive Numbers are ±5,±6,±7.

User Thaleshcv
by
2.5k points
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