Math Problem Statement

find two positive consecutive integers such that the squares of the first, added to 3 times the second, is 24.

Solution

Let the two consecutive positive integers be xx and x+1x+1. According to the problem:

  • The square of the first integer is x2x^2.
  • Three times the second integer is 3(x+1)3(x+1).

The sum of these two expressions is equal to 24: x2+3(x+1)=24x^2 + 3(x+1) = 24

Solving the equation:

  1. Expand the equation: x2+3(x+1)=x2+3x+3=24x^2 + 3(x+1) = x^2 + 3x + 3 = 24

  2. Subtract 24 from both sides: x2+3x+324=0x^2 + 3x + 3 - 24 = 0 x2+3x21=0x^2 + 3x - 21 = 0

  3. Solve the quadratic equation using the quadratic formula: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} Here, a=1a = 1, b=3b = 3, and c=21c = -21. Substituting into the formula: x=3±324(1)(21)2(1)x = \frac{-3 \pm \sqrt{3^2 - 4(1)(-21)}}{2(1)} x=3±9+842x = \frac{-3 \pm \sqrt{9 + 84}}{2} x=3±932x = \frac{-3 \pm \sqrt{93}}{2}

Since 93\sqrt{93} is not a perfect square, we cannot get a clean integer solution from this quadratic formula.

Checking simpler integer values:

We simplify our approach by testing small positive integers directly. Let’s test consecutive integers manually:

  1. For x=3x = 3:

    • First integer squared: 32=93^2 = 9
    • Three times the second integer: 3(4)=123(4) = 12
    • Sum: 9+12=219 + 12 = 21, not 24.
  2. For x=4x = 4:

    • First integer squared: 42=164^2 = 16
    • Three times the second integer: 3(5)=153(5) = 15
    • Sum: 16+15=3116 + 15 = 31, not 24.

Thus, none of the two initial

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Consecutive Integers

Formulas

Quadratic formula: x = (-b ± √(b^2 - 4ac)) / 2a

Theorems

Quadratic Formula Theorem

Suitable Grade Level

Grades 8-10