Question

A equação do 2º grau cuja raízes são x' = 2 e x'' = -1 é:
s (x - 1)(x - 2) = 0
(x - 2)(x + 1) = 0
(x + 3)(x - 3) = 0
(x - 1)(x + 1) = 0
(x - 2)(x + 2) = 0

Answer 1

$\large\boxed{\begin{array}{l}\underline{\sf Forma\,fatorada\,da\,equac_{\!\!,}\tilde ao\,de\,2^o\,grau}\\\rm dada\,a\,equac_{\!\!,}\tilde ao\,ax^2+bx+c=0\\\rm a\,forma\,fatorada\,\acute e\, a\cdot(x-x_1)\cdot(x-x_2)\\\rm onde\,x_1\,e\,x_2\,s\tilde ao\,as\,ra\acute izes.\\\rm x_1=2~~x_2=-1\\\rm(x-2)\cdot(x-(-1))=0\\\rm (x-2)\cdot(x+1)=0\end{array}}$