Mathematics

Question

Solve equation by completing the square round to the nearest hundredth if necessary
X2-4x-=5

1 Answer

  • Answer:

    x=-1 and x=5

    Step-by-step explanation:

    we have

    [tex]x^{2} -4x=5[/tex]

    Solve it by completing the square method

    We take the coefficient of x that is -4, divide it by 2 and then square it

    so

    [tex]-\frac{4}{2}=-2[/tex]

    square it

    [tex](-2)^2 = 4[/tex]

    Adds 4 both sides

    [tex]x^{2} -4x+4=5+4[/tex]

    Combine like terms right side

    [tex]x^{2} -4x+4=9[/tex]

    Rewrite as perfect squares

    [tex](x-2)^{2}=9[/tex]

    take square root both sides

    [tex]x-2=\pm3[/tex]

    [tex]x=2\pm3[/tex]

    therefore

    [tex]x=2+3=5[/tex]

    [tex]x=2-3=-1[/tex]