If a number is subtracted from it's square the result is 2. Find the number.

Question

parthkohli · Answer

$ \color{Black}{\Rightarrow x^2 - x  = 2}$

parthkohli · Answer

$ \color{Black}{\Rightarrow x^2 - x - 2 = 0}$

$ \color{Black}{\Rightarrow x^2 + x - 2x - 2 =0}$

$ \color{Black}{\Rightarrow x(x + 1) - 2(x + 1) = 0}$

$ \color{Black}{\Rightarrow ( x - 2)(x  + 1) = 0}$

$ \color{Black}{\Rightarrow x = 2,-1 }$

anonymous · Answer

So it's 2 or -1?

parthkohli · Answer

Yes.

anonymous · Answer

The square of -1 is -1 and -1 minus -1 is 0. Not 2.

parthkohli · Answer

$ \color{Black}{\Rightarrow (-1)^2 - (-1)}$

$ \color{Black}{\Rightarrow (-1)^2 + 1}$

$ \color{Black}{\Rightarrow (-1)(-1) + 1}$

$ \color{Black}{\Rightarrow 1 + 1}$

$ \color{Black}{\Rightarrow 2}$

anonymous · Answer

i guess