Question

Determine as raízes de cada equação
a) 6x+2-x=-2x-12
b) x² -x - 12 =0​

Answer 1

Resposta:

a)

$6x+2-x=-2x-12\\6x-x+2x=-12-2\\7x=-14\\x=\dfrac{14}{7} \\\boxed{x=-2}$

b)

$x^2 -x - 12 =0\\\\a=1\:\:b=-1\:\: c=-12\\\Delta=(-1)^2+(-4)\times(-12)\times1\\\Delta=1+48\\\Delta=49\\x=\dfrac{-(-1)\pm\sqrt{49} }{2\times1} \\x=\dfrac{1\pm7}{2} \\x'=\dfrac{1+7}{2} \iff \boxed{x'=4}\\x"=\dfrac{1-7}{2} \iff \boxed{x"=-3}$

Att Silver Sword

Explicação passo-a-passo: