distribute (x+1)(x-2)
(x+1)(x-2) = x(x-2) + 1(x-2)= x.x - x . 2 + 1. x - 1 . 2= x² - 2x + x -2= x²-x -2^_^
\(\mathfrak{solution} :\\\\(x+1)(x-2)\\=x(x-2)+1(x-2)\\=x^{2}-2x+x-2\\=x^{2}-x-2\\\\========================================\\\\\mathfrak{note:}\\\boxed{(x+a)(x-b)=x(x-b)+a(x-b)}\)
