Find the Roots: Solving the Quadratic Equation x² - 16 = 0

Question

Solve the following equation:

x216=0 x^2-16=0

Video Solution

Solution Steps

00:00 Find X
00:03 Isolate X
00:09 Extract root
00:14 When extracting a root there are always 2 solutions (positive, negative)
00:19 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Recognize the structure of the equation as a difference of squares.
  • Step 2: Factor the equation.
  • Step 3: Use the zero-product property to find the values of xx.

Now, let's work through each step:
Step 1: The equation given is x216=0x^2 - 16 = 0. This equation is a type of difference of squares, as it can be expressed in the form a2b2=(ab)(a+b)a^2 - b^2 = (a - b)(a + b).
Step 2: Recognizing 1616 as 424^2, we can factor the equation: x216=(x4)(x+4)=0x^2 - 16 = (x - 4)(x + 4) = 0.
Step 3: According to the zero-product property, if the product of two expressions is zero, then at least one of the expressions must be zero. Therefore, we set each factor equal to zero:
x4=0x - 4 = 0 or x+4=0x + 4 = 0.
Solving these simple linear equations gives x=4x = 4 and x=4x = -4.

Therefore, the solutions to the equation are x1=4 x_1 = -4 and x2=4 x_2 = 4 .

Answer

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