Factor x^2 + 5x -4?, please show steps?

Question

please show steps

Answer 1

Can't factor, use other means :

Question Number 1 :

For this equation x^2 + 5*x - 4 = 0 , answer the following questions :

A. Find the roots using Quadratic Formula !

B. Use completing the square to find the root of the equation !

Answer Number 1 :

The equation x^2 + 5*x - 4 = 0 is already in a*x^2+b*x+c=0 form.

As the value is already arranged in a*x^2+b*x+c=0 form, we get the value of a = 1, b = 5, c = -4.

1A. Find the roots using Quadratic Formula !

  By using abc formula the value of x is both

    x1 = (-b+sqrt(b^2-4*a*c))/(2*a) and x2 = (-b-sqrt(b^2-4*a*c))/(2*a)

  Since a = 1, b = 5 and c = -4,

  we need to subtitute a,b,c in the abc formula, with thos values.

  Which produce x1 = (-(5) + sqrt( (5)^2 - 4 * (1)*(-4)))/(2*1) and x2 = (-(5) - sqrt( (5)^2 - 4 * (1)*(-4)))/(2*1)

  Which make x1 = ( -5 + sqrt( 25+16))/(2) and x2 = ( -5 - sqrt( 25+16))/(2)

  Which make x1 = ( -5 + sqrt( 41))/(2) and x2 = ( -5 - sqrt( 41))/(2)

  It imply that x1 = ( -5 + 6.40312423743285 )/(2) and x2 = ( -5 - 6.40312423743285 )/(2)

  So we got the answers as x1 = 0.701562118716424 and x2 = -5.70156211871642

1B. Use completing the square to find the root of the equation !

  x^2 + 5*x - 4 = 0 ,divide both side with 1

  Which result in x^2 + 5*x - 4 = 0 ,

  We know that the coefficient of x is 5

  We have to use the fact that ( x + q )^2 = x^2 + 2*q*x + q^2 , and assume that q = 5/2 = 2.5

  By using that fact we turn the equation into x^2 + 5*x + 6.25 - 10.25 = 0

  Which is the same with ( x + 2.5 )^2  - 10.25 = 0

  So we will get (( x + 2.5 ) - 3.20156211871642 ) * (( x + 2.5 ) + 3.20156211871642 ) = 0

  Which is the same with ( x + 2.5 - 3.20156211871642 ) * ( x + 2.5 + 3.20156211871642 ) = 0

  So we just need to add up, and get ( x - 0.701562118716424 ) * ( x + 5.70156211871642 ) = 0

  The answers are x1 = 0.701562118716424 and x2 = -5.70156211871642

Answer 2

dont really remember how to but i know u gota put it into a quadratic equation

Answer 3

not factorable

-5(+ or -)sqrt(25-(-16)/2

-5(+ or -)sqrt(41)/2

Answer 4

You either have the signs wrong or you have to use the quadratic formula.  

Answer 5

(X+a)(X+b)=X^2 + aX + bX +ab=X^2+5X-4,so (a+b)=5 and ab= -4,

how about a=-5+41^1/2 and b=-5-41^1/2,then check it ,

{X-5+(41)^1/2} {X-5-(41)^1/2}