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3 years ago

Multiply (x + 3)(x – 3).

Mathematics

2 answers:

lyudmila [28]3 years ago

7 0

B would be correct the -3 x and 3 x cancel out

Lady_Fox [76]3 years ago

7 0

Answer:

The answer is B. $x^2-9$

Step-by-step explanation:

This problem represents a "the Sum and Difference of the same two terms".

If you encounter the same two terms and just the sign between them changes, rest assured that the result is the square of those two terms. Also, the second term will always be negative.

For example:

$(a-b)*(a+b)=a^2-b^2$

So, in this case:

$(x+3)*(x-3)\\x^2-3*x+3*x-9\\x^2-9$

Therefore, the answer is B. $x^2-9$

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The combined perimeter of the rectangle and triangle is 63 inches. The model shows the dimensions of the rectangle. What is the

katrin2010 [14]

*See diagram in the attachment

Answer:

27 inches

Step-by-step explanation:

Combined perimeter = perimeter of rectangle + perimeter of triangle = 63 inches

Perimeter of rectangle = 2(L + W)

L = 11 in.

W = 7 in.

Perimeter of rectangle = 2(11 + 7) = 36 in.

Let perimeter of the triangle be represented by x

Therefore:

36 + x = 63

Subtract 36 from each side

x = 63 - 36

x = 27

Perimeter of triangle = 27 inches

7 0

3 years ago

You play in a soccer tournament, that consists of 5 games. Each game you win with probability .6, lose with probability .3, and

nasty-shy [4]

Answer:

(a) The joint PMF of W, L and T is:

$P(W,\ L,\ T)={5\choose (n_{W}!\times n_{L}!\times n_{T}!)}\times [0.60]^{n_{W}}\times [0.30]^{n_{L}}\times [0.10]^{n_{T}}$

(b) The marginal PMF of W is:

$P(W=w)={5\choose n_{W}!}\times 0.60^{n_{W}}\times (1-0.60)^{n-n_{W}}$

Step-by-step explanation:

Let X = number of soccer games played.

The outcome of the random variable X are:

W = if a game won

L = if a game is lost

T = if there is a tie

The probability of winning a game is, P (W) = 0.60.

The probability of losing a game is, P (L) = 0.30.

The probability of a tie is, P (T) = 0.10.

The sum of the probabilities of the outcomes of X are:

P (W) + P (L) + P (T) = 0.60 + 0.30 + 0.10 = 1.00

Thus, the distribution of W, L and T is a appropriate probability distribution.

(a)

Now, the outcomes W, L and T are one experiment.

The distribution of n independent and repeated trials, each having a discrete number of outcomes, each outcome occurring with a distinct constant probability is known as a Multinomial distribution.

The outcomes of X follows a Multinomial distribution.

The joint probability mass function of W, L and T is:

$P(W,\ L,\ T)={n\choose (n_{W}!\times n_{L}!\times n_{T}!)}\times [P(W)]^{n_{W}}\times [P(L)]^{n_{L}}\times [P(T)]^{n_{T}}$

The soccer tournament consists of n = 5 games.

Then the joint PMF of W, L and T is:

$P(W,\ L,\ T)={5\choose (n_{W}!\times n_{L}!\times n_{T}!)}\times [0.60]^{n_{W}}\times [0.30]^{n_{L}}\times [0.10]^{n_{T}}$

(b)

The random variable W is defined as the number games won in the soccer tournament.

The probability of winning a game is, P (W) = p = 0.60.

Total number of games in the tournament is, n = 5.

A game is won independently of the others.

The random variable W follows a Binomial distribution.

The probability mass function of W is:

$P(W=w)={5\choose n_{W}!}\times 0.60^{n_{W}}\times (1-0.60)^{n-n_{W}}$

Thus, the marginal PMF of W is:

$P(W=w)={5\choose n_{W}!}\times 0.60^{n_{W}}\times (1-0.60)^{n-n_{W}}$

3 0

3 years ago

What is the value of 7(3x-4) + 4^3,when x = 6

RoseWind [281]

Answer:

162

Step-by-step explanation:

8 0

2 years ago

Read 2 more answers

Math question: Write the equation of the line with an undefined slope, passing through the point (2, 5).

lana [24]

When an equation has a line with an undefined slope, it means that the line is vertical.

(2,5); 2 is the x - coordinate and 5 is the y - coordinate

Slope - intercept form: y = mx + b

As shown above, the equation would've been written in slope - intercept form, where 'm' represents the slope and 'b' represents the y - intercept. However, in this case, the slope is undefined.
In the equation, you are ONLY looking for the x - intercept. Therefore, the x - intercept is 5, so that may be the equation of the line.

x = 5

4 0

3 years ago

An HMO charges $35 per doctor visit (d) and $15 per prescription (p). Which expression shows the total cost for prescriptions an

Alecsey [184]

Answer:

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Step-by-step explanation:

6 0

3 years ago