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3 years ago

Someone can help me with this please

Mathematics

1 answer:

Marina CMI [18]3 years ago

6 0

Answer:

x = -1 and x = 7

Step-by-step explanation:

2x^2 + 2x - 14x - 14

2x^2 - 12x -14

Divide through by 2 to simplify the expression

x^2 - 6x - 7

x^2 - 6x -7

Now, let's think of two numbers that when added up gives -6 and when multiplied gives -7

Yes! It's -7 and +1

-7 + 1 = -6 , and -7* 1 = -7

Now, lets substitute these numbers in the expression

x^2 -7x + x - 7

factorize

x(x - 7) + 1(x - 7)

(x + 1) (x - 7)

Now equate to zero

(x + 1) (x - 7) = 0

x + 1 = 0

subtract 1 from both sides

x +1 - 1 = 0 -1

x = -1

Also,

x - 7 = 0

Add 7 to both sides

x -7 + 7 = 0 + 7

x = 7

Hence, x = -1 and x =7

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scores on the act college entrance exam follow a bell-shaped distribution with mean 18 and standard deviation 6. Wayne's standar

WITCHER [35]

Answer:

His actual score is 15

Step-by-step explanation:

Here, we are interested in calculating Wayne’s actual score on the ACT

when we say the scores have being standardized, it means the score was reported in terms of the z-score and not the initial raw scores.

Now, mathematically, for the scores to have a negative z-score, it means it is actually below the mean.

The formula for the z-score or standard score is given below;

z-score = (x - mean)/SD

where in this case, x = ? which is the score we are looking for , z-score = -0.5 , mean score = 18 and standard deviation of the scores = 6

So, substituting these values into the z-score equation, we have;

-0.5 = (x-18)/6

x-18 = 6(-0.5)

x -18 = -3

x = -3 + 18

x = 15

7 0

3 years ago

What is the approximate value of x in the diagram below? (Hint: You will need

Delicious77 [7]

Answer:

B. 39.59

Step-by-step explanation:

So 43 degrees, you know the length of the opposite side (27) and the angle (43 degrees), the only unknown is the hypotenuse. So you're looking for a trigonometric ratio that uses the angle (all of them do, except technically the inverse don't), the opposite side, and the hypotenuse. Sine is defined as $\frac{opposite}{hypotenuse}$ . So let's plug in known values: