Question

11. Resolva as equações completas no conjunto R: a) 2x2 + 7x + 5 = 0 b) x2 + 2x − 8 = 0 c) −x2 + 10x − 24 = 0 d) −x2 − 2x + 3 = 0 e) y2 + 4y + 4 = 0 f) 3x2 − 8x + 10 = 0 g) 8x2 − 2x − 1 = 0

Answer 1

Resposta:

A) 1 e -2,5

B) 2 e -4

C) 4 e 6

D) -3 e -1

E) -2

F) o delta não tem raiz

G) 0,5 e 0,25

Explicação passo-a-passo:

Os cálculos estão nas fotos que eu coloquei.

ESPERO TER AJUDADO!!!

Answer 2

Para visualizar a resposta acesse

https://brainly.com.br/tarefa/31961348

$\tt{a)}~\sf{2x^2+7x+5}\\\sf{\Delta=49-40=9}\\\sf{x=\dfrac{-7\pm3}{4}}\\\sf{x_1=-1}\\\sf{x_2=-\dfrac{5}{2}}$

$\tt{b)}~\sf{x^2+2x-8=0}\\\sf{\Delta=4+32=36}\\\sf{x=\dfrac{-2\pm6}{2}}\\\sf{x_1=2}\\\sf{x_2=-4}$

$\tt{c)}~\sf{-x^2+10x-24=0\cdot(-1)}\\\sf{x^2-10x+24=0}\\\sf{\Delta=100-96=4}\\\sf{x=\dfrac{10\pm2}{2}}}\\\sf{x_1=6}\\\sf{x_2=4}$

$\tt{d)}~\sf{-x^2-2x+3=0\cdot(-1)}\\\sf{x^2+2x-3=0}\\\sf{\Delta=4+12=16}\\\sf{x=\dfrac{-2\pm4}{2}}\\\sf{x_1=1}\\\sf{x_2=-3}$

$\tt{e)}~\sf{y^2+4y+4=0}\\\sf{\Delta=16-16=0}\\\sf{y=\dfrac{-4}{2}=-2}$

$\tt{f)}~\sf{3x^2-8x+10=0}\\\sf{\Delta=64-120=-56\textless0}\\\sf{\not\exists ~x\in\mathbb{R}}$

$\tt{g)}~\sf{8x^2-2x-1=0}\\\sf{\Delta=4+32=36}\\\sf{x=\dfrac{2\pm6}{16}}\\\sf{x_1=\dfrac{1}{2}}\\\sf{x_2=-\dfrac{1}{4}}$