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oblicz równanie (2x +1)2=4*(x+2)*(x-2)



Odpowiedź :

PickSell

Odpowiedź:

(2x +1)2=4*(x+2)*(x-2)

4x + 2 = 4(x²-4)

4x+2 = 4x²-16

4x²-4x-18 = 0 /:2

2x²-2x-9 = 0

Δ= 4+9*2*4 = 4+72 = 76

√Δ = √76 = 2√19

[tex]x_{1}[/tex] = [tex]\frac{2-2\sqrt{19}}{4}[/tex] = [tex]\frac{1-\sqrt{19}}{2}[/tex]

[tex]x_{2}[/tex] = [tex]\frac{2+2\sqrt{19}}{4}[/tex] = [tex]\frac{1+\sqrt{19}}{2}[/tex]

Klaudia13114

Odpowiedź:

(2x +1)2=4·(x+2)·(x-2)

2x+1=2(x+2)(x-2)

2x+1=2(x²-4)

2x+1=2x²-8

-2x²+2x+9=0

2x²-2x-9=0

Δ=b²-4ac

Δ= 4+72=76

√Δ=2[tex]\sqrt{19}[/tex]

x1=[tex]\frac{2-2\sqrt{19} }{2}[/tex]=[tex]\frac{1-\sqrt{19} }{2}[/tex]

x2=[tex]\frac{2+2\sqrt{19} }{2}[/tex]=[tex]\frac{1+\sqrt{19} }{2}[/tex]

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