Resposta:

∆ = b²- 4.a.c

a= 5 b= -3, c= -2

∆= ( -3) ² - 4.5.-2

∆= 9- (-40)

∆ = 9 + 40

∆= 49

x= - b +- √∆

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2.a

x= 3+-7

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10

x'=3+7/10= 10/10

x''= 1

x''3-7/10= -4/10 = +2/5

x"= 2/5