Question

RESOLVA
x-1+2x²+7x-4=

Answer 1

x - 1 + 2x² + 7x - 4 = 0
2x² + 6x - 5 = 0

Δ = b2 - 4.a.c 
Δ = 62 - 4 . 2 . -5 
Δ = 36 - 4. 2 . -5 
Δ = 76
Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (-6 + √76)/2.2  
x'' = (-6 - √76)/2.2

x' = 2,717797887081348 / 4   
x'' = -14,717797887081348 / 4

x' = 0,679449471770337   
x'' = -3,679449471770337