Thread: I am a little stuck on this problem.

√13-x=X-1

(13-X)^2=(X-1)^2

3-X=X^2

I get stuck after this part. The answer is suppose to be 4, can I get a little help? Thank you.

Originally Posted by Past45

√13-x=X-1

That's quite confusingly shown;
show what's being square rooted with brackets; don't mix variables (like x and X):
√(13 - x) = x - 1
square both sides:
13 - x = x^2 - 2x + 1 : understand?
x^2 - x - 12 = 0
I'll give you the satisfaction of finishing it!

Don't forget also to consider the domain.