Math Problem Statement

the sum of squares of 2 consecutive numbers is 145, what are the numbers?

Solution

Let the two consecutive numbers be xx and x+1x+1.

The sum of the squares of these numbers is given by: x2+(x+1)2=145x^2 + (x+1)^2 = 145

First, expand the equation: x2+(x2+2x+1)=145x^2 + (x^2 + 2x + 1) = 145

Combine like terms: 2x2+2x+1=1452x^2 + 2x + 1 = 145

Subtract 145 from both sides to set the equation to zero: 2x2+2x+1145=02x^2 + 2x + 1 - 145 = 0 2x2+2x144=02x^2 + 2x - 144 = 0

Divide the entire equation by 2 to simplify: x2+x72=0x^2 + x - 72 = 0

Next, solve the quadratic equation using the quadratic formula x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}, where a=1a = 1, b=1b = 1, and c=72c = -72.

Calculate the discriminant: b24ac=124(1)(72)=1+288=289b^2 - 4ac = 1^2 - 4(1)(-72) = 1 + 288 = 289

Find the square root of the discriminant: 289=17\sqrt{289} = 17

Apply the quadratic formula: x=1±172x = \frac{-1 \pm 17}{2}

This gives us two solutions: x=1+172=162=8x = \frac{-1 + 17}{2} = \frac{16}{2} = 8 x=1172=182=9x = \frac{-1 - 17}{2} = \frac{-18}{2} = -9

Therefore, the two pairs of consecutive numbers are:

  1. x=8x = 8 and x+1=9x+1 = 9
  2. x=9x = -9 and x+1=8x+1 = -8

So, the numbers are either (8,9)(8, 9) or ( (-9,

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations

Formulas

Quadratic formula

Theorems

-

Suitable Grade Level

Grades 7-9