Question

ex 12 punctele a b c va rog am nevoie rapid cu ecuația de gradul 2

Answer 1

Răspuns:

Explicație pas cu pas:

a) 2x²-3x-2 = 0

a = 2 ; b = -3 ; c = -2 ; Δ = b²-4ac = (-3)²-4·2·(-2) = 9+16 = 25

√Δ = √25 = 5

x₁,₂ = (-b±√Δ)/2a = (3±5)/4 => x₁ = -1/2 ; x₂ = 2

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2x²+7x-4 = 0 ; a = 2 ; b = 7 ; c = -4 ; Δ = 49+32 = 81 ; √Δ = 9

x₁,₂ = (-7±9)/4 => x₁ = -4 ; x₂ = 1/2

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6x²-7x+2 = 0 ; a = 6 ; b = -7 ; c = 2 ; Δ = 49-48 = 1 ; √Δ = 1

x₁,₂ = (7±1)/12 => x₁ = 1/2 ; x₂ = 2/3

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b) 3x²-x-2 = 0 ; a = 3 ; b = -1 ; c = -2

Δ = (-1)²-4·3·(-2) = 1+24 = 25 ; √Δ = √25 = 5

x₁,₂ = (1±5)/6 => x₁ = -2/3 ; x₂ = 1

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4x²+5x-6 = 0 ; a = 4 ; b = 5 ; c = -6 ; Δ = 25+96 = 121 ; √Δ = 11

x₁,₂ = (-5±11)/8 => x₁ = -2 ; x₂ = 3/4

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2x²-5x-12 = 0 ; a = 2 ; b = -5 ; c = -12 ; Δ = 25+96 = 121 ; √Δ = 11

x₁,₂ = (5±11)/4 => x₁ = -3/2 ; x₂ = 4

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c) 3x²+4x-4 = 0 ; a = 3 ; b = 4 ; c = -4

Δ = 4²-4·3·(-4) = 16+48 = 64 => √Δ = √64 = 8

x₁,₂ = (-4±8)/6 => x₁ = -7/3 ; x₂ = 2/3

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2x²-9x+4 = 0 ; a = 2 ; b = -9 ; c = 4 ; Δ = 81-32 = 49 ; √Δ = 7

x₁,₂ = (9±7)/4 => x₁ = 1/2 ; x₂ = 4

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2x²+3x-5 = 0 ; a = 2 ; b = 3 ; c = -5 ; Δ = 9+40 = 49 ; √Δ = 7

x₁,₂ = (-3±7)/4 => x₁ = -5/2 ; x₂ = 1