Math Problem Statement

Macey wants to determine the solutions to the quadratic equation x2−3x−2=0 . Her first step is shown below.

x=−(−3)±(−3)2−4⋅1⋅−2√2⋅1

Compete her work to determine which of the following are the solutions to the equation. A.3±17√2

B.−3±17√2

C.−3±17√−2

D.3±−17√2

Solution

To complete Macey's work and solve the quadratic equation x23x2=0x^2 - 3x - 2 = 0, let's go through each step using the quadratic formula:

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

In this case:

  • a=1a = 1
  • b=3b = -3
  • c=2c = -2

Substitute these values into the formula:

x=(3)±(3)241(2)21x = \frac{-(-3) \pm \sqrt{(-3)^2 - 4 \cdot 1 \cdot (-2)}}{2 \cdot 1}

Simplify the terms:

  1. Calculate (3)=3-(-3) = 3.

    x=3±(3)241(2)21x = \frac{3 \pm \sqrt{(-3)^2 - 4 \cdot 1 \cdot (-2)}}{2 \cdot 1}

  2. Evaluate (3)2=9(-3)^2 = 9 and 41(2)=8-4 \cdot 1 \cdot (-2) = 8, so the expression inside the square root is:

    9+8=179 + 8 = 17

  3. Substitute back:

    x=3±172x = \frac{3 \pm \sqrt{17}}{2}

Thus, the solutions are:

x=3±172x = \frac{3 \pm \sqrt{17}}{2}

Answer

The correct answer is: A. 3±172\frac{3 \pm \sqrt{17}}{2}


Do you want more details on any part of the solution?

Related Questions

  1. How do you derive the quadratic formula?
  2. How can you determine if a quadratic equation has real or complex roots?
  3. What is the importance of the discriminant b24acb^2 - 4ac in quadratic equations?
  4. How would the solutions change if cc was positive?
  5. What are other methods to solve a quadratic equation?

Tip

Always check the discriminant (b24acb^2 - 4ac) first; if it’s positive, the equation has two real solutions; if zero, one real solution; if negative, two complex solutions.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Square Roots

Formulas

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

Theorems

Discriminant Analysis in Quadratic Equations

Suitable Grade Level

Grades 9-10