Question

Resolva a equação 2x² – 6x – 56 = 0 .
a) X'=-7 e X''=4.
b) X'=2 e X''=-6 X'=7
c) X''=-4 X'=7 e X''=-6

Answer 1

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2x² - 6x - 56 = 0

x² - 3x - 28 = 0

x = -(-3) ± √(-3)² - 4(1)(-28)

2(1)

x = 3 ± √9 + 112

2

x = 3 ± √121

2

x = 3 ± 11

2

x = 1,5 ± 5,5

S = { 7 ; -4 }

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Att: MarcosPCV