SOLUTION: x2-2x-13=0 i can not figure out how to figure this out

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Question 418439: x2-2x-13=0 i can not figure out how to figure this out
Found 2 solutions by stanbon, MathLover1:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
x^2-2x-13=0
----------
Use the quadratic formula:
x = [2 +- sqrt(4 -4*-13)]/2
----
x = [2 +- sqrt(56)]/2
----
x = [2 +- 2sqrt(14)]/2
---
x = [1 +- sqrt(14)]
=======================================
Cheers,
Stan H

Answer by MathLover1(20849)   (Show Source): You can put this solution on YOUR website!

Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:


Starting with the general quadratic





the general solution using the quadratic equation is:







So lets solve ( notice , , and )





Plug in a=1, b=-2, and c=-13




Negate -2 to get 2




Square -2 to get 4 (note: remember when you square -2, you must square the negative as well. This is because .)




Multiply to get




Combine like terms in the radicand (everything under the square root)




Simplify the square root (note: If you need help with simplifying the square root, check out this solver)




Multiply 2 and 1 to get 2


So now the expression breaks down into two parts


or



Now break up the fraction



or



Simplify



or



So the solutions are:

or





so, or

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