Use quadratic formula to solve the equation?

Question

Im not sure what that means. Here is the problem. Could someone give me steps?

x^2 - x - 3=0

PLEASE HELP!!!

Answer 1

The quadratic formula works for equations with an x^2, x, and # value. It is: -b+/-sq.rt.b^2-4ac/2a

or: negative b plus or minus the square root of (b squared minus four times a times c) and put all that over two times a.

this is your equation with a,b and c

ax^2-bx-c

which means: a=1, b= -1, c= -3

plug those into the formula: -(-1) a negative of a negative b would be a positive b, or 1. 1+/-sq.rt. (-1*-1) a negative times a negative is always a positive. 1+/-sq.rt.(1-4*1*-3), 1+/-sq.rt.(1--12). subtracting a negative is the same as adding a positive: 1+/-sq.rt.13/2*1--don't forget that the whole thing is over 2a! so your answer is 1+/-sq.rt.13/2 or: one plus or minus the square root of 13, all over 2.

I hope that this helps!!

Answer 2

The quadratic formula states: For ax2 + bx + c = 0, the value of x is given by:

               ________  

-b +/- / b^2 - 4ac

______________

           2a

Or... b squared plus or minus the square root of b squared minus 4 times a times c all divided by 2 times a

So for your equation a=1 b= -1 and c= -3

                 ___________

-*-1 +/- /-1^2 - (4*1*-3)

___________________

            (2*1)

Then

        ______________

1 +/-/ (-1*-1) - (-12)

___________________

              2

Then

         ______

1 +/- / 1 + 12

____________

          2

Then

       __                                 __

1 + /13                OR       1 - /13

_______                          ______

    2                                     2

Sorry if that's confusing, but I really hope that it helps.  Basically, you just figure out which is a, which is b, and which is c and then plug them into the equation to get your answer. Sorry if that's confusing, but I really hope that it helps.