Resposta :

3x-y = 7 --> -y = 7-3x --> y = 3x-7

x²-2y = 6

x²-2(3x-7) = 6

x²-6x+14 = 6

x²-6x+14-6 = 0

x²-6x+8 = 0

delta = (-6)² - 4.1.8

delta = 36 - 42

delta = 4

 

x = (-(-6)+/-\/4)/2

x = (6+/-2)/2

x' = (6+2)/2 = 4

x" = (6-2)/2 = 2

 

y = 3x-7

y' = 3.4-7 = 12-7 = 5

y" = 3.2-7 = 6-7 = -1

 

S: {(4,5),(2,-1)}

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