Equations reducible to quadratics (1 Viewer)

[Fsadni]

Me and the back of the book are having problems.

The question is Solve
(x-3)^2 - (x-3) -2 =0
The working out should be
Let u= x-3
Therefore:
u^2 - u -2 =0

I then factorise to
(u-1)(u+2)
Therefore
u=1 or u=-2

But since u= x-3

And that's what I get up to before the book and I have problems.
it says x= 5 or x=2

I say x=4 or x=1

Which is correct and why?

 

[BIGTYMA]

your working out is wrong. the back of the book is right. just sub in x=5 ad x=2 to the equation (x-3)^2 - (x-3) -2 =0. if LHS=RHS then your answer is right.

you have a mistake during factorise step.