Question

Resolvendo a equação X² - 9X - 10 = 0, encontramos: *

A) 12 e - 4

11 e - 3

C) 10 e - 1

D) 9 e 2

Pfvrr Rápidoooo
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Answer 1

• $\small{x^{2}-9x-10=0}$

◼️Coeficientes

• $\small{a=+1}$

• $\small{b=-9}$

• $\small{c=-10}$

◼️ Discriminante

• $\small{\Delta=b^{2}-4.a.c}$

• $\small{\Delta=(-9)^{2}-4.(1).(-10)}$

• $\small{\Delta=81+40}$

• $\small{\Delta=121}$

◼️Raízes da equação

• $\small{x'=[-(-9)+\sqrt{121}]/2.(1)}$

• $\small{x'=[9+11]/2}$

• $\small{x'=20/2}$

• $\small{\underbrace{x'=10}}$

✅

• $\small{x"=[-(-9)-\sqrt{121}]/2.(1)}$

• $\small{x"=[9-11]/2}$

• $\small{x"=-2/2}$

• $\small{\underbrace{x"=-1}}$

◼️ alternativa C