Question

Calcule x^2+3x-10 * 1 ponto 2 e 5 2 e -5

Answer 1

Oie, Td Bom?!

$x {}^{2} + 3x - 10 = 0$

$x {}^{2} + 5x - 2x - 10 = 0$

$x \: . \: (x + 5) - 2(x + 5) = 0$

$(x + 5) \: . \: (x - 2) = 0$

• $x + 5 = 0⇒x = - 5$

• $x - 2 = 0⇒x = 2$

$S = \left \{ - 5 \: ,\: 2 \right \}$

Att. Makaveli1996

Answer 2

Explicação passo-a-passo:

$\sf x^2+3x-10=0$

$\sf \Delta=3^2-4\cdot1\cdot(-10)$

$\sf \Delta=9+40$

$\sf \Delta=49$

$\sf x=\dfrac{-3\pm\sqrt{49}}{2\cdot1}=\dfrac{-3\pm7}{2}$

$\sf x'=\dfrac{-3+7}{2}~\Rightarrow~x'=\dfrac{4}{2}~\Rightarrow~\red{x'=2}$

$\sf x"=\dfrac{-3-7}{2}~\Rightarrow~x"=\dfrac{-10}{2}~\Rightarrow~\red{x"=-5}$