Math Problem Statement

Solve the quadratic equation by completing the square. 2 x squared plus 3 x minus 2equals0 Question content area bottom Part 1 The solution set is

Solution

To solve the quadratic equation 2x2+3x2=02x^2 + 3x - 2 = 0 by completing the square, follow these steps:

Step 1: Move the constant to the other side

Start with the equation: 2x2+3x2=02x^2 + 3x - 2 = 0 Move the constant 2-2 to the other side of the equation: 2x2+3x=22x^2 + 3x = 2

Step 2: Factor out the leading coefficient from the quadratic and linear terms

Factor out the 22 from the left-hand side: 2(x2+32x)=22(x^2 + \frac{3}{2}x) = 2

Step 3: Complete the square

To complete the square, take half of the coefficient of xx (which is 32\frac{3}{2}), square it, and add it inside the parentheses. The number to add is: (34)2=916\left(\frac{3}{4}\right)^2 = \frac{9}{16} Add 916\frac{9}{16} inside the parentheses, and also subtract it outside the parentheses to balance the equation: 2(x2+32x+916)2(916)=22\left(x^2 + \frac{3}{2}x + \frac{9}{16}\right) - 2\left(\frac{9}{16}\right) = 2

Step 4: Simplify the equation

Now, rewrite the expression inside the parentheses as a perfect square and simplify: 2(x+34)21816=22\left(x + \frac{3}{4}\right)^2 - \frac{18}{16} = 2 Simplify the fraction: 2(x+34)298=22\left(x + \frac{3}{4}\right)^2 - \frac{9}{8} = 2

Step 5: Move the constant to the other side

Add 98\frac{9}{8} to both sides: 2(x+34)2=2+982\left(x + \frac{3}{4}\right)^2 = 2 + \frac{9}{8} Combine the constants: 2(x+34)2=168+98=2582\left(x + \frac{3}{4}\right)^2 = \frac{16}{8} + \frac{9}{8} = \frac{25}{8}

Step 6: Solve for xx

Divide both sides by 2: (x+34)2=2516\left(x + \frac{3}{4}\right)^2 = \frac{25}{16} Take the square root of both sides: x+34=±54x + \frac{3}{4} = \pm \frac{5}{4}

Step 7: Isolate xx

Now solve for xx by subtracting 34\frac{3}{4} from both sides: x=34±54x = -\frac{3}{4} \pm \frac{5}{4}

This gives two solutions: x=3+54=24=12x = \frac{-3 + 5}{4} = \frac{2}{4} = \frac{1}{2} x=354=84=2x = \frac{-3 - 5}{4} = \frac{-8}{4} = -2

Final Answer:

The solution set is: x=12,2x = \frac{1}{2}, -2

Would you like more details or have any questions?

Related Questions:

  1. How do you complete the square for equations with leading coefficients different from 1?
  2. What is the geometric interpretation of completing the square?
  3. How do you solve quadratic equations using the quadratic formula?
  4. What are other methods to solve quadratic equations?
  5. How do you check the solutions of a quadratic equation?

Tip:

Always verify your solutions by substituting them back into the original equation!

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Completing the Square

Formulas

Quadratic equation formula ax^2 + bx + c = 0
Completing the square method

Theorems

Square Root Theorem

Suitable Grade Level

Grades 9-10