Question

URGENTE


A menor das raizes da equação x²-x-12=0 é:

A) 3
B) 4
C) -3
D) -4
E) NDR

Answer 1

$x^2-x-12=0\ \to\ a=1,\ b=-1,\ c=-12$

$\boxed{x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}}$

$x=\dfrac{-(-1)\pm\sqrt{(-1)^2-4(1)(-12)}}{2(1)}$

$x=\dfrac{1\pm\sqrt{49}}{2}=\dfrac{1\pm7}{2}$

$\boxed{x=-3}\ \text{ou}\ \boxed{x=4}$

A menor raiz é $x=-3$.

Letra C.