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3 years ago

Give the function f(x) =2x^2+4x-7 find f(-4)? A -55 B -7 C 9 D 25

Mathematics

1 answer:

erma4kov [3.2K]3 years ago

4 0

Answer:

Step-by-step explanation:

To evaluate f??(- 4) substitute x = - 4 into f(x), that is

f(- 4) = 2(- 4)² + 4(- 4) - 7 = (2 × 16) - 16 - 7 = 32 - 23 = 9 → C

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Answer:

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Step-by-step explanation:

The equation given to you is in y=mx+b form.

m is the slope which in this case would be 2/9.

b is the y-intercept which in this case would be 1/3

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Suppose that prior to conducting a coin-flipping experiment, we suspect that the coin is fair. How many times would we have to f

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Answer: b) 84

Step-by-step explanation:

Let p be the prior estimate of the required proportion.

As per given , we have

p =0.5 (The probability of getting heads on a fair coin is 0.5)

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Critical z-value (using z-value table ) : $z_{\alpha/2}=1.645$

Confidence interval width : w= 0.18

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3 years ago

Lucy makes green paint by mixing yellow and blue paint in the ratio 5:2. Blue paint costs

ahrayia [7]

Answer:

No, she won’t make a profit

Step-by-step explanation:

Here, we are interested in determining if Lucy made a profit or a loss.

The cost of blue paint is 30 pounds for 5 liters. This means that a liter of blue paint is 30/5 = 6 pounds per liter

The cost of yellow paint is 28 pounds per 7 liters, the cost per liter is 28/7 = 4 pounds per liter

Now, in her mixing, she mixes 5 parts of yellow paint and 2 parts of blue paint.

This means that she mixed them the ratio as follows per liter;

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For blue we have 2/(5+2) = 2/7

Now since a liter of yellow paint cost 4 pounds

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The total cost in pounds in this;

20/7 + 12/7 = 32/7 = £4.57 pounds to 2 decimal place

Now she sells her green paint product at £4.5 per liter. Since this is less than the cost price of production which is £4.57, she is running at a loss

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