Question

qual o resposta da conta (x-3) (x+4) - 10 = (1-x) (x+2)

Answer 1

Aplicar a distributiva:
 
(x-3) (x+4) - 10 = (1-x) (x+2)

x² + 4x - 3x - 12 - 10 = x + 2 - x² - 2x
x² + x - 22 = -x² + x - 2x + 2
x² + x - 22 = - x² - x + 2
x² + x² + x + x - 22 - 2 = 0
2x² + 2x - 24 = 0

a = 2
b = 2
c = -24

Δ = b² -4 .a . c
Δ = 2² -4 . 2 . (-24)
Δ = 4 - 8 . (-24)
Δ = 4 + 192
Δ = 196

$\mathtt{\dfrac{-b+-~\sqrt{\Delta}}{2~.~a}~~=~~\dfrac{-2+-~\sqrt{196}}{2~~.~2}~~=~~\dfrac{-2+-~14}{4}} \\ \\ \\ \mathtt{x = \dfrac{-2+14}{4}~~=~~\dfrac{12}{4}~~=~~3} \\ \\ \\ \mathtt{x'' = \dfrac{-2-14}{4}~~=~~-\dfrac{16}{4}~~=~~-4}$


Resposta: S{-4 e 3}