SOLUTION: I have to complete the square for this problem.. x^2+13=(-14x)I have this I added 14 x to both sides which left me with x^2+14x+13=0 then I subtracted 13 from both sides wh

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I have to complete the square for this problem.. x^2+13=(-14x)I have this I added 14 x to both sides which left me with x^2+14x+13=0 then I subtracted 13 from both sides wh      Log On


   

Question 162104: I have to complete the square for this problem..
x^2+13=(-14x)I have this
I added 14 x to both sides which left me with
x^2+14x+13=0
then I subtracted 13 from both sides which left me with
x^2+14x+49=13+49
so I have factor 14x which is (x+7)
so (x+7)^2= (13+49)=62
so I have to get the square root of both sides which leaves me with
(x+7)=square root of 62
now I do not know what to do.
please help soon
Answer by tutor_paul(519) About Me  (Show Source):
You can put this solution on YOUR website!
You made a mistake when you substracted 13 from both sides. You should have:
x%5E2%2B14x%2B13=0
x%5E2%2B14x=-13
*note the -13 term on the right
Divide coefficient of x by 2 and square it. Add this result to both sides:
x%5E2%2B14x%2B49=49-13
Re-write left side as a perfect square and simplify right side:
%28x%2B7%29%5E2=36
Take square root of both sides:
x+7= +/-6
Solve for x for boh the plus and minus case:
highlight%28x=-1%29
highlight%28x=-13%29
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Good Luck,
tutor_paul@yahoo.com