-x²+13x-30=04x²+20x+25=04x²-4x+1=0.... Pergunta de ideia deDeniseminosso

May 2020 1 48 Report

-x²+13x-30=0

4x²+20x+25=0

4x²-4x+1=0

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Verified answer

-x²+13x-30=0 .(-1)
x² - 13x + 30 = 0

a = 1 b = - 13 c= + 30
Δ = b² - 4.a.c
Δ = (-13)² - 4.(1).(+30)
Δ = 169 - 120
Δ = 49

x = - b ± √Δ
2.a

x = - (-13) ± √49
2.1

x = + 13 ± 7
2

x' = 13 + 7 = 20 = 10
2   2

x" = 13 - 7 = 6 = 3
2 2

S[3, 10]

4x²+20x+25=0

a = 4 b= + 20 c = + 25
Δ = b² - 4.a.c
Δ = (20)² - 4.(4).(+25)
Δ = 400 - 400
Δ = 0

x = - b ± √Δ
2.a

x = - (+20) ± √0
2.4

x = - 20 ± 0
8

x' = -20 + 0  = - 20   ÷ 4 = - 5
  8      8 ÷ 4 2

x" = -20 - 0   = - 20   ÷   4 = - 5
8 8   ÷ 4 2

S[- 5/2 ou - 2,5]

4x²-4x+1=0

a = 1 b = - 4 c = + 1
Δ = b² - 4.a.c
Δ = (-4)² - 4.(4).(+1)
Δ = 16 - 16
Δ = 0

x = - b ± √Δ
2.a

x = - (-4) ± √0
2.4

x = + 4 ± 0
8

x' = 4 + 0  = 4   ÷ 4 = 1
  8 8 ÷ 4 2

x" = 4 - 0   =   4   ÷ 4 =   1
8 8   ÷ 4 2

S[1/2]

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