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4 years ago

State the intervals for which the given quadratic is positive and when it is negative.

Mathematics

1 answer:

goblinko [34]4 years ago

3 0

Answer:

Positive at (-9, 2)
Negative at ( -oo, -9) or (2, + oo)

Step-by-step explanation:

Given function

y= -2x^2 - 14x + 36

Getting zero's

-2x^2 - 14x + 36 = 0
x^2 + 7x - 18 = 0

x = ( -7 ± √(49 +72))/2 = ( -7 ± 11)/2
x = - 9 and x = 2

As the x^2 has negative coefficient, the function is positive between -9 and 2

- 9 < x < 2 or
(-9, 2)

And it is negative at:

x < -9 and
x > 2
or
( -oo, -9) or (2, + oo)

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3 years ago

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Step-by-step explanation:

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3 years ago

Jennifer and Kamlee are walking to school. After 20 minutes, Jennifer has walked 4/5 miles. After 25 minutes, Kamlee has walked

Nimfa-mama [501]

Answer:

Jennifer's speed is 2.4 miles/hour

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Step-by-step explanation:

To find their speed,

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Also, to determine the speed in miles per hour (miles/hour), we will convert the time spent by each of them to hour (NOTE: 60 minutes = 1 hour)

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3 years ago

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Answer:

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Step-by-step explanation:

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3 years ago

Read 2 more answers

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Answer:

$8.75

Step-by-step explanation:

Let x = the amount the man originally had

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y = amount he has after 1st proposition = x + x - 10 = 2x - 10

He repeats this procedure, now with $2x-10 in his pocket...

z = amount he has after 2nd proposition = (2x - 10) + (2x - 10) - 10 = 4x - 30

He repeats this procedure, now with $4x-30 in his pocket...but this time he is left with zero dollars...

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8x - 70 = 0,

x = $8.75

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3 years ago