Solve the Quadratic Equation: 10x² - 65x + 135 = 4x² + 13x - 45

Question

Solve the following equation:

10x265x+135=4x2+13x45 10x^2-65x+135=4x^2+13x-45

Video Solution

Solution Steps

00:00 Find X
00:03 Arrange the equation so the right side equals 0
00:14 Group terms
00:29 Simplify as much as possible
00:40 Identify equation components
00:48 Use the roots formula
00:55 Substitute appropriate values and solve for X
01:15 Calculate products and squares
01:26 Calculate square root of 49
01:33 Find the 2 possible solutions
01:45 This is one solution
01:48 This is the second solution and the answer to the question

Step-by-Step Solution

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

  • Step 1: Simplify the equation by gathering all terms on one side.
  • Step 2: Combine like terms to express the equation in standard quadratic form.
  • Step 3: Apply the quadratic formula to find the values of xx.

Now, let's work through each step:

Step 1: Starting with the equation 10x265x+135=4x2+13x4510x^2 - 65x + 135 = 4x^2 + 13x - 45, subtract 4x24x^2, 13x13x, and add 4545 on both sides:

10x265x+1354x213x+45=010x^2 - 65x + 135 - 4x^2 - 13x + 45 = 0

Step 2: Combine like terms:

(10x24x2)+(65x13x)+(135+45)=0(10x^2 - 4x^2) + (-65x - 13x) + (135 + 45) = 0

This simplifies to 6x278x+180=06x^2 - 78x + 180 = 0.

Step 3: Identify the coefficients a=6a = 6, b=78b = -78, and c=180c = 180. Use the quadratic formula:

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

Substitute the values:

x=(78)±(78)24618026x = \frac{-(-78) \pm \sqrt{(-78)^2 - 4 \cdot 6 \cdot 180}}{2 \cdot 6}

x=78±6084432012x = \frac{78 \pm \sqrt{6084 - 4320}}{12}

x=78±176412x = \frac{78 \pm \sqrt{1764}}{12}

x=78±4212x = \frac{78 \pm 42}{12}

Calculating the two possible values:

x1=78+4212=12012=10x_1 = \frac{78 + 42}{12} = \frac{120}{12} = 10

x2=784212=3612=3x_2 = \frac{78 - 42}{12} = \frac{36}{12} = 3

Therefore, the solutions to the equation are x1=10x_1 = 10 and x2=3x_2 = 3.

The correct answer according to the provided choices is x1=10x_1=10 and x2=3x_2=3, which corresponds to choice 4.

Answer

x1=10 x_1=10 x2=3 x_2=3