Question

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Answer 1

Resposta:

Explicação passo a passo:

1) b)

-2x^2 - 7x + 4= 0

a= -2; b = -7; c = 4

∆= b^2-4ac

∆= (-7)^2-4.(-2).4

∆= 49 + 8.4

∆= 49+32

∆= 81

X =[-b+/- √∆]/2a

x =[-(-7)+/- 9]/2.(-2)

x = (7 +/-9)/(-4)

x ' = (7+9)/(-4)= -16/4= - 4

x " = (7-9)/(-4)= -2/(-4)=1/2

Xv = - b/2a = -(-7)/2.(-2)= 7/4= 1,75

Yv = - ∆/4a = -81/4.(-2)=81/8= 10,12

2) c)

X^2-18x= 0

x.(x-18)=0

x = 0

x-18=0

x=18

R.: C)

S= (0,18)