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3 years ago

I need help someone help

Mathematics

2 answers:

oee [108]3 years ago

6 0

Answer:

Step-by-step explanation:

The sum of 8 and 5

(8 + 5)

11 times the sum of 8 and 5

11 x (8 + 5)

Tanzania [10]3 years ago

4 0

Answer:

The correct answer is D

Step-by-step explanation:

It's d because the 8+5 is in parenthesis that means you do that first before multiplying since the keyword is "sum".

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Help me please with this

AysviL [449]

Since both angle are congruent (equal/same), which means that both side is equal to 40 degrees, we will put the equation like this:

5x - 5 = 40

Now we’ll solve for x:

5x - 5 = 40
+ 5 + 5 (Add 5 to both sides)

5x = 45
—- —— (Five both side by 5)
5 5

x = 9

Now we left with x, so x is equal to 9.

8 0

2 years ago

2x 7 = -3solve for x , what is x

o-na [289]

Is it 2x +7= -3? If so the answer is -5

7 0

2 years ago

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

Che sum of two numbers is 2. If one number is subtracted from the other, their difference is - 8. Find the numbeRs

goldfiish [28.3K]

I wanna say 10 or ether -10 since if it was subtracted from 2 then it would equal -8

7 0

2 years ago

Read 2 more answers

Please help me with this:(

dolphi86 [110]

Answer:

Y = 32.7°

Step-by-step explanation:

We will apply the Cosine law in the given triangle XYZ,

x = 90 ft

y = 55 ft

z = 50 ft

We have to find the measure of angle Y.

y² = x² + z² - 2xzCosY

(55)² = (90)² + (50)² - 2(90)(50)cosY

3025 = 8100 + 2500 - 9000.cosY

9000.cosY = 10600 - 3025

cosY = $\frac{7575}{9000}$

= 0.84167

Y = $\text{cos}^{-1}(0.84167)$

Y = 32.68 ≈ 32.7°

Therefore, measure of angle Y = 32.7°

5 0

3 years ago