Hi
You need to start by multiply all terms by (x-2)(x+1) and cancel
x(x+1)(x-1)(x-2)=-1(x-2)(x+1)
2x²-2x+2=-x²+x+2
Now you need to subtract -x²+x+2
2x²-2x+2-(-x²+x+2)=-x²+x+2-(-x²+x+2)
3x²-3x=0
Now factorize
3x(x-1)=0
3x=0 or x-1=0
x= 0 or x=1
I hope that's help and good luck :0