Respostas

  • Usuário do Brainly
2014-07-17T17:45:59-03:00
N°=x

x.x-14=5x

x²-14=5x
x²-5x-14=0
Δ=25+56
Δ=81
√Δ=9

x'= \frac{5+9}{2} = \frac{14}{2} =7

x"= \frac{5-9}{2} = \frac{-4}{2}=-2

R= O n° é 7 ou -2

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