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coldgirl [10]
3 years ago
7

Use the quadratic formula to solve x^2+8x+9=0

Mathematics
1 answer:
Tju [1.3M]3 years ago
4 0
None of your options, not via complete the square nor quadratic the formula.

Solve for x over the real numbers:
x^2 + 8 x + 9 = 0

x = (-8 ± sqrt(8^2 - 4×9))/2 = (-8 ± sqrt(64 - 36))/2 = (-8 ± sqrt(28))/2:
x = (-8 + sqrt(28))/2 or x = (-8 - sqrt(28))/2

sqrt(28) = sqrt(4×7) = sqrt(2^2×7) = 2sqrt(7):
x = (2 sqrt(7) - 8)/2 or x = (-2 sqrt(7) - 8)/2

Factor 2 from -8 + 2 sqrt(7) giving 2 (sqrt(7) - 4):
x = 1/22 (sqrt(7) - 4) or x = (-2 sqrt(7) - 8)/2

(2 (sqrt(7) - 4))/2 = sqrt(7) - 4:
x = sqrt(7) - 4 or x = (-2 sqrt(7) - 8)/2

Factor 2 from -8 - 2 sqrt(7) giving 2 (-sqrt(7) - 4):
x = sqrt(7) - 4 or x = 1/22 (-sqrt(7) - 4)

(2 (-sqrt(7) - 4))/2 = -sqrt(7) - 4:

Answer: x = sqrt(7) - 4 or x = -sqrt(7) - 4_____________________________________________________

Solve for x:
x^2 + 8 x + 9 = 0

Subtract 9 from both sides:
x^2 + 8 x = -9

Add 16 to both sides:
x^2 + 8 x + 16 = 7

Write the left hand side as a square:
(x + 4)^2 = 7

Take the square root of both sides:
x + 4 = sqrt(7) or x + 4 = -sqrt(7)

Subtract 4 from both sides:
x = sqrt(7) - 4 or x + 4 = -sqrt(7)

Subtract 4 from both sides:
Answer:  x = sqrt(7) - 4 or x = -4 - sqrt(7)
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Step-by-step explanation:

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Step-by-step explanation:

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Data from the Centers for Medicare and Medicaid Services indicates that the annual per capita out-of-pocket expenses for health
Talja [164]

Answer:

During the year 2021.

Step-by-step explanation:

As we have a function that defines the annual per capita out-of-pocket expenses for health care, we can work with it.

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El valor numérico de la expresión 〖P(y)=y〗^2-7y+10 para y=2 es: a. P(2)=9 b. P(2)=0 c. P(2)=-2 d. P(2)=-5
nika2105 [10]

Answer:

Opción b, P(2) = 0

Step-by-step explanation:

Tenemos la expresión:

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Para encontrar el valor P(2), simplemente debemos remplazar todas las "y" en la expresión de arriba por el valor 2, asi obtenemos:

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P(2) = 0

La opción correcta es b.

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