Solve the Quadratic Equation: (1/2)x² - 3x + 2.5 = 0

Question

Solve the following equation:

12x23x+212=0 \frac{1}{2}x^2-3x+2\frac{1}{2}=0

Video Solution

Solution Steps

00:00 Find X
00:06 Multiply to eliminate fractions
00:14 Identify the coefficients
00:26 Use the roots formula
00:45 Substitute appropriate values according to the given data and solve
01:09 Calculate the square and products
01:21 Calculate the square root of 16
01:31 These are the 2 possible solutions (addition,subtraction)
01:54 And this is the solution to the question

Step-by-Step Solution

To solve the quadratic equation 12x23x+212=0 \frac{1}{2}x^2 - 3x + 2\frac{1}{2} = 0 , we will follow these steps:

  • Step 1: Convert the mixed number to an improper fraction or decimal for uniformity in calculations.
  • Step 2: Identify the coefficients a a , b b , and c c .
  • Step 3: Apply the quadratic formula to find the roots x1 x_1 and x2 x_2 .

Step 1: Rewriting the equation with decimals, we have:

12x23x+2.5=0 \frac{1}{2}x^2 - 3x + 2.5 = 0

Step 2: The equation is already in standard form, where a=12 a = \frac{1}{2} , b=3 b = -3 , and c=2.5 c = 2.5 .

Step 3: Apply the quadratic formula:

x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Calculate the discriminant (Δ \Delta ):

Δ=b24ac=(3)24122.5=95=4 \Delta = b^2 - 4ac = (-3)^2 - 4 \cdot \frac{1}{2} \cdot 2.5 = 9 - 5 = 4

Since the discriminant is positive, there are two real solutions.

Calculate the roots:

x=(3)±4212 x = \frac{-(-3) \pm \sqrt{4}}{2 \cdot \frac{1}{2}}

x=3±21 x = \frac{3 \pm 2}{1}

Thus, the solutions are:

  • x1=3+21=5 x_1 = \frac{3 + 2}{1} = 5
  • x2=321=1 x_2 = \frac{3 - 2}{1} = 1

Therefore, the solutions to the equation are x1=5 x_1 = 5 and x2=1 x_2 = 1 .

From the provided choices, the correct answer is:

x1=5,x2=1 x_1=5,x_2=1

Answer

x1=5,x2=1 x_1=5,x_2=1