Question

Solve 2x2 + 4x = 30 using the Quadratic Formula.

Answer 1

Answer:

$x=-5, 3$

General Formulas and Concepts:

Pre-Algebra

• Order of Operations: BPEMDAS

Algebra I

• Standard Form: ax² + bx + c = 0
• Quadratic Formula: $x=\frac{-b\pm\sqrt{b^2-4ac} }{2a}$

Step-by-step explanation:

Step 1: Define equation

2x² + 4x = 30

Step 2: Rewrite into Standard Form

2x² + 4x - 30 = 0

Step 3: Define variables

a = 2

b = 4

c = -30

Step 4: Solve for x

1. Substitute:                    $x=\frac{-4\pm\sqrt{4^2-4(2)(-30)} }{2(2)}$
2. Evaluate:                       $x=\frac{-4\pm\sqrt{16-4(2)(-30)} }{2(2)}$
3. Multiply:                        $x=\frac{-4\pm\sqrt{16+240} }4}$
4. Add:                              $x=\frac{-4\pm\sqrt{256} }4}$
5. Evaluate:                      $x=\frac{-4\pm16 }4}$
6. Factor:                          $x=\frac{4(-1\pm4)}4}$
7. Divide:                          $x=(-1\pm4)$
8. Add/Subtract:              $x=-5, 3$

And we have our final answer!