Solving a Quadratic Equation

Alejandro Mascort

November 5, 2024

Practice solving a quadratic equation using the quadratic formula.

Solve the following quadratic equation:

x25x+6=0x^2 - 5x + 6 = 0

Find the values of x that satisfy this equation.

Show Solution

To solve this quadratic equation, we’ll use the quadratic formula:

x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Where aa, bb, and cc are the coefficients in the standard form of a quadratic equation: ax2+bx+c=0ax^2 + bx + c = 0.

For our equation x25x+6=0x^2 - 5x + 6 = 0:

  • a=1a = 1
  • b=5b = -5
  • c=6c = 6

Let’s substitute these values into the quadratic formula:

x=(5)±(5)24(1)(6)2(1)x = \frac{-(-5) \pm \sqrt{(-5)^2 - 4(1)(6)}}{2(1)}

x=5±25242x = \frac{5 \pm \sqrt{25 - 24}}{2}

x=5±12x = \frac{5 \pm \sqrt{1}}{2}

x=5±12x = \frac{5 \pm 1}{2}

This gives us two solutions:

x1=5+12=62=3x_1 = \frac{5 + 1}{2} = \frac{6}{2} = 3

x2=512=42=2x_2 = \frac{5 - 1}{2} = \frac{4}{2} = 2

Therefore, the solutions to the equation x25x+6=0x^2 - 5x + 6 = 0 are:

x=3 or x=2x = 3 \text{ or } x = 2

You can verify these solutions by substituting them back into the original equation:

For x=3x = 3: (3)25(3)+6=915+6=0(3)^2 - 5(3) + 6 = 9 - 15 + 6 = 0

For x=2x = 2: (2)25(2)+6=410+6=0(2)^2 - 5(2) + 6 = 4 - 10 + 6 = 0

Both solutions satisfy the equation, confirming our answer.