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Alex787 [66]
3 years ago
13

Formúla General a) 4x²=9x-2=0 b) X²+8x-84=0​

Mathematics
1 answer:
makkiz [27]3 years ago
7 0

Answer:<em> </em><em>a)</em> x=\dfrac{-9 \pm\sqrt{113} }{8}

             <em> b) x₁ = - 14; x₂ = 6.</em>

Step-by-step explanation:

a) 4x² + 9x - 2 = 0

x=\dfrac{-b \pm \sqrt{b^{2}-4ac } }{2a} \\\\a=4; \: \: b=9; \: \: c=-2\\x =\dfrac{-9 \pm \sqrt{9^{2}-4 \cdot 4 \cdot (-2) } }{2 \cdot 4} =\dfrac{-9 \pm\sqrt{113} }{8}

b) x² + 8x - 84 = 0

x=\dfrac{-b \pm \sqrt{b^{2}-4ac } }{2a} \\\\a=1; \: \: b=8; \: \: c=-84\\\\x =\dfrac{-8 \pm \sqrt{8^{2}-4 \cdot 1 \cdot (-84) } }{2 \cdot 1} =\dfrac{-8 \pm\sqrt{400} }{2}=\dfrac{-8 \pm 20}{2} =-4 \pm 10\\\\x_{1} =-14\\x_{2} =6

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hram777 [196]

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Step-by-step explanation:

D( x )

x+2 = 0

x = 0

x+2 = 0

x+2 = 0

x+2 = 0 // - 2

x = -2

x = 0

x = 0

x in (-oo:-2) U (-2:0) U (0:+oo)

(9*x-7)/(x+2)+15/x = 9 // - 9

(9*x-7)/(x+2)+15/x-9 = 0

(x*(9*x-7))/(x*(x+2))+(15*(x+2))/(x*(x+2))+(-9*x*(x+2))/(x*(x+2)) = 0

x*(9*x-7)+15*(x+2)-9*x*(x+2) = 0

9*x^2-9*x^2+8*x-18*x+30 = 0

30-10*x = 0

(30-10*x)/(x*(x+2)) = 0

(30-10*x)/(x*(x+2)) = 0 // * x*(x+2)

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3 0
3 years ago
I need help! Someone help me please
liberstina [14]

Answer:

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4 0
3 years ago
Read 2 more answers
899 round to the nearest ten
algol [13]
900 because 9 is greater than 5 so it rounds to my answer.
6 0
2 years ago
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Viefleur [7K]
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8 0
2 years ago
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Brrunno [24]
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17 is the answer

I used PEMDAS

P - Parenthesis

E - Exponents

M - Multiplication

D - Division

A - Addition

S - Subtraction

[in order that your supposed to do]




5 0
3 years ago
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