Math Problem Statement

Solve the quadratic equations: 1. 4x^2 + 8x + 3 = 0, 2. 2x^2 + 3x - 20 = 0, 3. 5x^2 - 80 = 0, 4. 5x^2 + 9x = -4, 5. 9x^2 + 4x - 16 = 0

Solution

The image you uploaded contains five quadratic equations that need to be solved. I will solve each equation step-by-step.

1. 4x2+8x+3=04x^2 + 8x + 3 = 0

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

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

Here, a=4a = 4, b=8b = 8, and c=3c = 3.

x=8±824(4)(3)2(4)x = \frac{-8 \pm \sqrt{8^2 - 4(4)(3)}}{2(4)} x=8±64488x = \frac{-8 \pm \sqrt{64 - 48}}{8} x=8±168x = \frac{-8 \pm \sqrt{16}}{8} x=8±48x = \frac{-8 \pm 4}{8}

So, the solutions are:

x1=8+48=48=12x_1 = \frac{-8 + 4}{8} = \frac{-4}{8} = -\frac{1}{2}

x2=848=128=32x_2 = \frac{-8 - 4}{8} = \frac{-12}{8} = -\frac{3}{2}

2. 2x2+3x20=02x^2 + 3x - 20 = 0

Using the quadratic formula:

x=3±324(2)(20)2(2)x = \frac{-3 \pm \sqrt{3^2 - 4(2)(-20)}}{2(2)} x=3±9+1604x = \frac{-3 \pm \sqrt{9 + 160}}{4} x=3±1694x = \frac{-3 \pm \sqrt{169}}{4} x=3±134x = \frac{-3 \pm 13}{4}

So, the solutions are:

x1=3+134=104=52x_1 = \frac{-3 + 13}{4} = \frac{10}{4} = \frac{5}{2}

x2=3134=164=4x_2 = \frac{-3 - 13}{4} = \frac{-16}{4} = -4

3. 5x280=05x^2 - 80 = 0

This equation can be simplified by dividing through by 5:

x216=0x^2 - 16 = 0

Factor it:

(x4)(x+4)=0(x - 4)(x + 4) = 0

The solutions are:

x1=4x_1 = 4 x2=4x_2 = -4

4. 5x2+9x=45x^2 + 9x = -4

First, move everything to one side to set the equation to zero:

5x2+9x+4=05x^2 + 9x + 4 = 0

Now, use the quadratic formula:

x=9±924(5)(4)2(5)x = \frac{-9 \pm \sqrt{9^2 - 4(5)(4)}}{2(5)} x=9±818010x = \frac{-9 \pm \sqrt{81 - 80}}{10} x=9±110x = \frac{-9 \pm \sqrt{1}}{10} x=9±110x = \frac{-9 \pm 1}{10}

So, the solutions are:

x1=9+110=810=45x_1 = \frac{-9 + 1}{10} = \frac{-8}{10} = -\frac{4}{5}

x2=9110=1010=1x_2 = \frac{-9 - 1}{10} = \frac{-10}{10} = -1

5. 9x2+4x16=09x^2 + 4x - 16 = 0

Using the quadratic formula:

x=4±424(9)(16)2(9)x = \frac{-4 \pm \sqrt{4^2 - 4(9)(-16)}}{2(9)} x=4±16+57618x = \frac{-4 \pm \sqrt{16 + 576}}{18} x=4±59218x = \frac{-4 \pm \sqrt{592}}{18} x=4±16×3718=4±43718x = \frac{-4 \pm \sqrt{16 \times 37}}{18} = \frac{-4 \pm 4\sqrt{37}}{18} x=2±2379x = \frac{-2 \pm 2\sqrt{37}}{9}

So, the solutions are:

x1=2+2379x_1 = \frac{-2 + 2\sqrt{37}}{9} x2=22379x_2 = \frac{-2 - 2\sqrt{37}}{9}


Would you like more details on any of these solutions? Here are five additional questions you might find interesting:

  1. How can the discriminant help determine the nature of the roots for a quadratic equation?
  2. How would you solve a quadratic equation by completing the square?
  3. What is the significance of the coefficients in a quadratic equation?
  4. How do you factorize a quadratic equation?
  5. Can you apply the quadratic formula to non-real solutions?

Tip: The discriminant b24acb^2 - 4ac is key in determining whether the roots of a quadratic equation are real and distinct, real and equal, or complex.

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Math Problem Analysis

Mathematical Concepts

Quadratic Equations
Algebra

Formulas

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

Theorems

Quadratic Formula Theorem
Zero Product Property

Suitable Grade Level

Grades 8-10