SOLUTION: In the following problem I am trying to solve for x but something isnt working right when I go back tocheck my work. The following are the ways that I tried but it back fired. Can

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Question 111355: In the following problem I am trying to solve for x but something isnt working right when I go back tocheck my work. The following are the ways that I tried but it back fired. Can you please assist.
the equation is {x^2-7x-3=0}
This is what I have
x^2-7x-3=0
-6x^2-3=0
-9x=0
x=0
and
x^2-7x-3=0
7x^2+3=0
10x^2
I know that both are wrong but cant get the right answer, can you please advise me as to what I am doing wrong?
Thank you so much!!
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!
The main problem you are having is that you are combining terms. You cannot add and to get since they are different terms. So you either have to factor (which doesn't work all of the time) or use the quadratic formula (which works for any quadratic formula).

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=-7, and c=-3

Negate -7 to get 7

Square -7 to get 49 (note: remember when you square -7, 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