Solve the Quadratic Inequality: x²-8x+12>0 Step by Step

Question

Solve the following equation:

x^2-8x+12>0

Video Solution

Step-by-Step Solution

Let's proceed to solve the inequality x28x+12>0 x^2 - 8x + 12 > 0 .

  • Start by factoring the quadratic: x28x+12 x^2 - 8x + 12 .
  • Identify the factors of 12 that sum to 8: 6 6 and 2 2 . This results in: (x6)(x2)=0 (x - 6)(x - 2) = 0 .

The factorization gives us the critical points x=6 x = 6 and x=2 x = 2 . These points divide the number line into three intervals: x<2 x < 2 , 2<x<6 2 < x < 6 , and x>6 x > 6 .

Now, we evaluate the sign of the product (x6)(x2) (x - 6)(x - 2) in each interval:

  • For x<2 x < 2 : Both (x6) (x - 6) and (x2) (x - 2) are negative, so their product is positive.
  • For 2<x<6 2 < x < 6 : (x2) (x - 2) is positive, (x6) (x - 6) is negative, so their product is negative.
  • For x>6 x > 6 : Both (x6) (x - 6) and (x2) (x - 2) are positive, so their product is positive.

The inequality (x6)(x2)>0 (x - 6)(x - 2) > 0 holds for x<2 x < 2 and x>6 x > 6 .

Thus, the solution to the inequality x28x+12>0 x^2 - 8x + 12 > 0 is x<2 x < 2 or x>6 x > 6 .

Therefore, the correct answer is x<2,6<x \boxed{x < 2, 6 < x} .

Answer

x < 2,6 < x


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