Question

Determinando no campo dos números inteiros, o conjunto verdade da equação, x² - 2(x + 1) = 2x + 3, temos
a)V= {0-1}
b)V= {5,-1}
c)V={2,3}
d)V= {1,3}
Alguem me da o Calculo Por favor

Answer 1

Explicação passo-a-passo:

$x^{2} -2(x+1)=2x+3\\\\x^{2} -2x-2-2x-3=0\\\\x^{2} -4x-5=0$

Resolvendo usando Bhaskara:

$\Delta=b^{2}-4.a.c\\\\\Delta=(-4)^{2}-4.1.(-5)=16+20=36\\\\x=\dfrac{-b\pm\sqrt{\Delta} }{2.a}\\\\x'=\dfrac{-(-4)+\sqrt{36} }{2.1}\\\\x'=\dfrac{4+6 }{2}\\\\x'=\dfrac{10}{2}\\\\\boxed{x'=5}\\\\\text ou\\\\x''=\dfrac{-(-4)-\sqrt{36} }{2.1}\\\\x''=\dfrac{4-6 }{2}\\\\x''=\dfrac{-2}{2}\\\\\boxed{x''=-1}\\\\\boxed{\boxed{V=\{5,-1\}}}$

Resposta B