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3 years ago

Using the quadratic equation formula to solve 7x^2-x=7, what are the values of x

Mathematics

1 answer:

Gennadij [26K]3 years ago

8 0

quadratic formula:

x = -b ± √(b² - 4ac)

7x² - x = 7

subtract 7 from both sides:

7x² - x - 7 = 0

plug values into the quadratic formula:

x = -(-1) ± √((-1)²- 4(7)(-7))

2(7)

simplify:

x = 1 ± √(197)

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notka56 [123]

Answer:

12) y=3x-15

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Step-by-step explanation:

Parallel lines always have the same slopes but different y-intercepts. So, we can make the equation (b is y-intercept of new equation):

12) y=3x+b

14) y=-1/2x+b

16) y=13x+b

now, we can plug in each of the coordinates given to these equations.

12) (4,-3): 4 is x, -3 is y.

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simplify: b=0

16) (9,12): 9 is x, 12 is y

12=13(9)+b

simplify: b=-105

Now, plug in those numbers to your equation for b value.

12) y=3x-15

14) y=-1/2x

16) y=13x-105

*for 14 we don't need to write anything after -1/2x because b=0*

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Step-by-step explanation:

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Step-by-step explanation:

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The price of a computer component is decreasing at a rate of 15% per year. State whether this decrease is linear or exponential

Margaret [11]

Answer:

Since the price is given by an exponential function, the decline in price is exponential.

The component will cost $36.8475 in three years.

Step-by-step explanation:

The equation for the price of a component has the following format:

$P(t) = P(0)(1-r)^{t}$

In which P(t) is the price after t years, P(0) is the initial price, and r is the rate that the price decreases.

Since the price is given by an exponential function, the decline in price is exponential.

The price of a computer component is decreasing at a rate of 15% per year.

This means that $r = 0.15$

Component costs $60 today

So P(0) = 60. Then

$P(t) = P(0)(1-r)^{t}$

$P(t) = 60(1-0.15)^{t}$

$P(t) = 60(0.85)^{t}$

What will it cost in three years?

This is P(3).

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$P(3) = 60(0.85)^{3} = 36.8475$

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Step-by-step explanation:

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