anonymous 5 years ago solve for x x^2-1=x+1

1. anonymous

You should really try working these out a bit on your own and say where you've gotten stuck. If you just submit all your problems you won't actually be learning anything. $x^{2} - 1 = x + 1 \rightarrow x^{2}-x = 0 \rightarrow x(x-1) = 0 \rightarrow x \in \left\{ 0,1 \right\}$

2. anonymous

i am stuck on this one

3. anonymous

Yes, but where did you get stuck?

4. anonymous

im confused on this whole problem can you teach me how to do this?

5. anonymous

Actually my solution is wrong. It should be $x^2 - 1 = x + 1 \rightarrow x^2 - x -2 = 0 \rightarrow x = (1 \pm \sqrt{9})/2 \rightarrow x \in \left\{ -1,2 \right\}$

6. anonymous

You move everything to one side of the equal sign and you see that you have a standard quadratic, with a=1, b=-1, c=-2. $x = (-b \pm \sqrt{b^2 - 4ac})/2a$