Solve the Quadratic Equation: Find x in 3x^2 - 17x + 28 = x + 4

Question

Solve the following equation:

3x217x+28=x+4 3x^2-17x+28=x+4

Video Solution

Solution Steps

00:00 Find X
00:03 Arrange the equation so the right side equals 0
00:10 Group terms
00:21 Simplify as much as possible
00:28 Identify equation components
00:36 Use the roots formula
00:48 Substitute appropriate values and solve for X
01:00 Calculate the products and squares
01:15 Calculate the square root of 4
01:19 Find the 2 possible solutions
01:24 This is one solution
01:28 This is the second solution and the answer to the question

Step-by-Step Solution

To solve the equation 3x217x+28=x+4 3x^2 - 17x + 28 = x + 4 , follow these steps:

  • Step 1: Simplify the equation.
    Begin by moving all terms to one side of the equation to obtain a standard form quadratic equation:
    3x217x+28x4=0 3x^2 - 17x + 28 - x - 4 = 0
  • Simplify further:
    3x218x+24=0 3x^2 - 18x + 24 = 0
  • Step 2: Identify coefficients.
    The equation is now in the standard form ax2+bx+c=0 ax^2 + bx + c = 0 where a=3 a = 3 , b=18 b = -18 , and c=24 c = 24 .
  • Step 3: Use the quadratic formula to solve for x x .
    The quadratic formula is given by:
    x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
  • Calculate the discriminant b24ac b^2 - 4ac :
    (18)24(3)(24)=324288=36 (-18)^2 - 4(3)(24) = 324 - 288 = 36
  • Since the discriminant is positive, there are two solutions.
  • Apply the quadratic formula:
    x=(18)±362(3)=18±66 x = \frac{-(-18) \pm \sqrt{36}}{2(3)} = \frac{18 \pm 6}{6}
  • Calculate the two possible solutions:
    x1=18+66=4 x_1 = \frac{18 + 6}{6} = 4
    x2=1866=2 x_2 = \frac{18 - 6}{6} = 2

Therefore, the solutions to the equation are x1=4 x_1 = 4 and x2=2 x_2 = 2 .

Answer

x1=4 x_1=4 , x2=2 x_2=2