Question

Need help with quadratic equation:
x*squared* - 5 = 2x

Answer 1

do you know how to solve quadratic equation?

Answer 2

basically what you want to do is put all the terms onto one side. therefore:
\[x ^{2}-2x-5=0\]

after that, what you want to do is identify the numbers in front of the terms [called coefficients].

infront of \[x ^{2}\] there's a 1. in front of x, there's a -2, and -5.

so,

A=1
B=-2
C=-5

therefore using the quadratic equation:
\[\left( -b \pm \sqrt{b^{2}-4(a)(c)} \right) / (2)(a) \]

plug in those values and solve.

so:

\[\left( 2 \pm \sqrt{4-4(1)(-5)} \right) / (2)(1) \]



\[\left( 2 \pm \sqrt{24} \right) / (2) \]

and so after simplifiying:

\[\left( 2 \pm (2)\sqrt{6} \right) / (2) \]
you can factor out a 2 and you'll also be canceling out a the denominator.


\[\left( 2 (1\pm \sqrt{6} \right) / (2) \]
the 2's cancel out leaving you with the answer:


\[\left( 1\pm \sqrt{6} \right) \]

so your answers are:

\[\left( x=1+ \sqrt{6} \right) \]
\[\left( x=1- \sqrt{6} \right) \]

Answer 3

heh sorry that took a while, i type slow. : \