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2 years ago

7y + 2x − 10y + 3x2 − 10x

Mathematics

1 answer:

Anni [7]2 years ago

5 0

Answer:

3x^2-8x-3y

Step-by-step explanation:

combine like turms and rearrange

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Target is having a holiday sale and is marking down

BaLLatris [955]

Answer:

$375

Step-by-step explanation:

Convert the 25% discount into a decimal, which is 0.25
Multiply the original listed price ($500) by the discount as a decimal (0.25), which is $125
Subtract the original list price ($500) by $125 (the discount as a number). This is $375, which is the answer.

7 0

3 years ago

Read 2 more answers

What is 30 percent of 83?

ololo11 [35]

Answer:

24.9

Step-by-step explanation:

See the image below:)

7 0

3 years ago

Read 2 more answers

Consider a discrete random variable x with pmf px (1) = c 3 ; px (2) = c 6 ; px (5) = c 3 and 0 otherwise, where c is a positive

PtichkaEL [24]

Looks like the PMF is supposed to be

$\mathbb P(X=x)=\begin{cases}\dfrac c3&\text{for }x\in\{1,5\}\\\\\dfrac c6&\text{for }x=2\\\\0&\text{otherwise}\end{cases}$

which is kinda weird, but it's not entirely clear what you meant...

Anyway, assuming the PMF above, for this to be a valid PMF, we need the probabilities of all events to sum to 1:

$\displaystyle\sum_{x\in\{1,2,5\}}\mathbb P(X=x)=\dfrac c3+\dfrac c6+\dfrac c3=\dfrac{5c}6=1\implies c=\dfrac65$

Next,

$\mathbb P(X>2)=\mathbb P(X=5)=\dfrac c3=\dfrac25$

$\mathbb E(X)=\displaystyle\sum_{x\in\{1,2,5\}}x\,\mathbb P(X=x)=\dfrac c3+\dfrac{2c}6+\dfrac{5c}3=\dfrac{7c}3=\dfrac{14}5$

$\mathbb V(X)=\mathbb E\bigg((X-\mathbb E(X))^2\bigg)=\mathbb E(X^2)-\mathbb E(X)^2$
$\mathbb E(X^2)=\displaystyle\sum_{x\in\{1,2,5\}}x^2\,\mathbb P(X=x)=\dfrac c3+\dfrac{4c}6+\dfrac{25c}3=\dfrac{28c}3=\dfrac{56}5$
$\implies\mathbb V(X)=\dfrac{56}5-\left(\dfrac{14}5\right)^2=\dfrac{84}{25}$

If $Y=X^2+1$ , then $X^2=Y-1\implies X=\sqrt{Y-1}$ , where we take the positive root because we know $X$ can only take on positive values, namely 1, 2, and 5. Correspondingly, we know that $Y$ can take on the values $1^2+1=2$ , $2^2+1=5$ , and $5^2+1=26$ . At these values of $Y$ , we would have the same probability as we did for the respective value of $X$ . That is,

$\mathbb P(Y=y)=\begin{cases}\dfrac c3&\text{for }y=2\\\\\dfrac c6&\text{for }y=5\\\\\dfrac c3&\text{for }y=26\\\\0&\text{otherwise}\end{cases}$

Part (5) is incomplete, so I'll stop here.

8 0

3 years ago

3 − m = −2 (m + 6); m = −15 Yes or No

Nimfa-mama [501]

Answer:

3 − m = −2 (m + 6); m = −15 Yes

5 (p + 3) = −35; p = −4 No

8q = 3 (10 + q); q = 6 Yes

Step-by-step explanation:

3 − m = −2 (m + 6)

3 - m = -2m - 12

m = -15

Answer is Yes

5 (p + 3) = −35

5p + 15 = -35

5p = - 50

p = -10

Answer is No

8q = 3 (10 + q)

8q = 30 + 3q

5q = 30

q = 6

Answer is Yes

5 0

3 years ago

X(x – 4) and x2 - 4x define the same function.

ycow [4]

Answer:

Yes, because $x(x -4)$ is equivalent to $x^2-4x$

Step-by-step explanation:

$x(x -4)$ and $x^2-4x$

$x(x -4) = x^2 - 4x$

Hope this helps!

5 0

2 years ago