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2 years ago

Solve for x show work 2x=-6

Mathematics

2 answers:

umka2103 [35]2 years ago

7 0

Answer:

-3

Step-by-step explanation:

2x=-6

transpose 2 to LHS

$x = \frac{ - 6}{2 } \\ =x = - 3$

denis-greek [22]2 years ago

4 0

Answer:

x = - 3

Step-by-step explanation:

2x = - 6 ( divide both sides by 2 )

x = - 3

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What is the nearest whole percent of 62

charle [14.2K]

The nearest whole percent would just be 62%

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2 years ago

Read 2 more answers

Let X and Y be discrete random variables. Let E[X] and var[X] be the expected value and variance, respectively, of a random vari

Ulleksa [173]

Answer:

(a) $E[X+Y]=E[X]+E[Y]$

(b) $Var(X+Y)=Var(X)+Var(Y)$

Step-by-step explanation:

Let X and Y be discrete random variables and E(X) and Var(X) are the Expected Values and Variance of X respectively.

(a)We want to show that E[X + Y ] = E[X] + E[Y ].

When we have two random variables instead of one, we consider their joint distribution function.

For a function f(X,Y) of discrete variables X and Y, we can define

$E[f(X,Y)]=\sum_{x,y}f(x,y)\cdot P(X=x, Y=y).$

Since f(X,Y)=X+Y

$E[X+Y]=\sum_{x,y}(x+y)P(X=x,Y=y)\\=\sum_{x,y}xP(X=x,Y=y)+\sum_{x,y}yP(X=x,Y=y).$

Let us look at the first of these sums.

$\sum_{x,y}xP(X=x,Y=y)\\=\sum_{x}x\sum_{y}P(X=x,Y=y)\\\text{Taking Marginal distribution of x}\\=\sum_{x}xP(X=x)=E[X].$

Similarly,

$\sum_{x,y}yP(X=x,Y=y)\\=\sum_{y}y\sum_{x}P(X=x,Y=y)\\\text{Taking Marginal distribution of y}\\=\sum_{y}yP(Y=y)=E[Y].$

Combining these two gives the formula:

$\sum_{x,y}xP(X=x,Y=y)+\sum_{x,y}yP(X=x,Y=y) =E(X)+E(Y)$

Therefore:

$E[X+Y]=E[X]+E[Y] \text{ as required.}$

(b)We want to show that if X and Y are independent random variables, then:

$Var(X+Y)=Var(X)+Var(Y)$

By definition of Variance, we have that:

$Var(X+Y)=E(X+Y-E[X+Y]^2)$

$=E[(X-\mu_X +Y- \mu_Y)^2]\\=E[(X-\mu_X)^2 +(Y- \mu_Y)^2+2(X-\mu_X)(Y- \mu_Y)]\\$Since we have shown that expectation is linear$\\=E(X-\mu_X)^2 +E(Y- \mu_Y)^2+2E(X-\mu_X)(Y- \mu_Y)]\\=E[(X-E(X)]^2 +E[Y- E(Y)]^2+2Cov (X,Y)$

Since X and Y are independent, Cov(X,Y)=0

$=Var(X)+Var(Y)$

Therefore as required:

$Var(X+Y)=Var(X)+Var(Y)$

7 0

2 years ago

Help me please !!<br> I need this ASAP please helpppp

Kobotan [32]

Answer:

Step-by-step explanation:

$y=(2x-3)/5$

$5y=2x-3$

$(5y+3)/2=x$

$(5x+3)/2=y$

$f^{-1}(x)=(5x+3)/2$

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2 years ago

3/4 divied be 8/14. please give me answer

marusya05 [52]

Answer:

1 5/16

Step-by-step explanation:

3/4 / 8/14 is the same as

3/4 * 14/8 = 42 /32 1 5/16

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1 year ago

Help pleasejfjffjfjfjjffj

Darya [45]

The answer is -1.1
To get that i just subtracted 2.4 by 1.3 and then just carried over the negative sign

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2 years ago