Solve the Quadratic Equation: -81x² + 54x - 9 = 0

Question

Solve the following equation:

81x2+54x9=0 -81x^2+54x-9=0

Video Solution

Solution Steps

00:00 Find X
00:03 Pay attention to the coefficients
00:13 Use the root formula
00:26 Substitute appropriate values according to the given data and solve for X
00:51 Calculate the products and the square
01:17 And this is the solution to the question

Step-by-Step Solution

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

  • Step 1: Identify the coefficients a=81 a = -81 , b=54 b = 54 , and c=9 c = -9 .
  • Step 2: Calculate the discriminant D=b24ac D = b^2 - 4ac .
  • Step 3: Apply the quadratic formula to find the solution for x x .

Step 1: We have a=81 a = -81 , b=54 b = 54 , and c=9 c = -9 .

Step 2: Calculate the discriminant:

D=b24ac=5424(81)(9) D = b^2 - 4ac = 54^2 - 4(-81)(-9)

=29162916=0 = 2916 - 2916 = 0

Since the discriminant is zero, there is exactly one real solution, indicating a perfect square trinomial.

Step 3: Apply the quadratic formula:

x=b±D2a=54±0162 x = \frac{-b \pm \sqrt{D}}{2a} = \frac{-54 \pm \sqrt{0}}{-162}

x=54162=13 x = \frac{-54}{-162} = \frac{1}{3}

Therefore, the solution to the problem is x=13 x = \frac{1}{3} .

Answer

x=13 x=\frac{1}{3}