How do you factor x^2-5x-8?

Comments

• xwonderer

  June 2021

  so, x^2-5x-8

  first solve it

  x^2-5x-8=0

  D= b^2 - 4*a*c

  = 25-4*1*-8

  = 57

  your x1 then becomes = (-b+ √D) /(2a) = (5 + √57)/2

  x2= (-b- √D) /(2a) = (5- √57)/2

  so

  x^2-5x-8 = (x - (5- √57)/2) ( x - (5 + √57)/2)

  Hope it helped
• scarface

  June 2021

  Factor:

  x^2 - 5x - 8

  We can solve by using the Quadratic Formula:

  x = -b+/-sqrt b^2 - 4ac / 2a

  Therefore:

  a = 1

  b = -5

  c = -8

  First, we need to compute the discriminant: b^2 - 4ac

  b^2 - 4ac = (-5)^2 - 4 * 1 * (-8)

  (-5)(-5) = 25

  -4 * (-8) = 32

  25 + 32 = 57

  Discriminant d = 57 is greater than zero. That means that there are two solutions:

  x = -(-5) +/ sqrt 57 / 2

  x = -(-5) + sqrt 57 /2

  x = 6.27491721763537

  x = -(-5) - sqrt 57 /2

  x = -1.27491721763537

  Therefore Quadratic expression:

  1x^2 + (-5)x + -(8)

  can be factored using the Quadratic Formula.
• groove-to-the-trance

  June 2021

  This doesn't factor out evenly so let's use the quadratic formula:

  x = (-b±√(b²-4ac))/ 2a

  Plug it in:

  x = (5 ± √(25 -4(1)(-8)))/2

  When we solve all that we'll get (5±√57)/2

  Hope I helped!
• the-guy-watching-you

  June 2021

  it doesn't factor into even numbers. so if you have to solve for zeros you need to use the quadratic equation.

  the format for factoring is x^2+(a+b)x+ab = (x+b)(x+a)

  hope this helps.
• guillermo

  June 2021

  It's prime!