Math Problem Statement

Solve the quadratic equation 2x^2 - 2x - 7 = 0 using the quadratic formula.

Solution

The image you provided shows the following quadratic equation:

2x22x7=02x^2 - 2x - 7 = 0

You are asked to solve it using the quadratic formula.

The quadratic formula is:

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

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

For your equation, we have:

  • a=2a = 2
  • b=2b = -2
  • c=7c = -7

Now, we substitute these values into the quadratic formula:

x=(2)±(2)24(2)(7)2(2)x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(2)(-7)}}{2(2)} x=2±4+564x = \frac{2 \pm \sqrt{4 + 56}}{4} x=2±604x = \frac{2 \pm \sqrt{60}}{4}

Simplifying the square root of 60: 60=4×15=215\sqrt{60} = \sqrt{4 \times 15} = 2\sqrt{15}

Now substitute: x=2±2154x = \frac{2 \pm 2\sqrt{15}}{4}

We can simplify further: x=24±2154x = \frac{2}{4} \pm \frac{2\sqrt{15}}{4} x=12±152x = \frac{1}{2} \pm \frac{\sqrt{15}}{2}

Thus, the two possible solutions are: x=1+152orx=1152x = \frac{1 + \sqrt{15}}{2} \quad \text{or} \quad x = \frac{1 - \sqrt{15}}{2}

These are the solutions for the given quadratic equation.

Would you like further details on any steps or have any questions? Here are some related questions to expand your learning:

  1. What happens when the discriminant b24acb^2 - 4ac is negative in the quadratic formula?
  2. How can you simplify square roots of non-perfect squares in the quadratic formula?
  3. What is the geometric interpretation of the quadratic formula solutions on a graph?
  4. How would you solve a quadratic equation by factoring instead of using the quadratic formula?
  5. What are some practical applications of the quadratic formula in real life?

Tip: Always check if factoring is an easier method before applying the quadratic formula!

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations

Formulas

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

Theorems

Quadratic Formula Theorem

Suitable Grade Level

Grades 8-10