2+2! ANSWER FAST OR MY TACHER WILL KILL ME

I have to get this so I pass help plz

pshichka [43]

Answer:

$\boxed{\sf x=-2}$

$\boxed{\sf y=-4}$

Step-by-step explanation:

First, Let's solve for x in -2x+2y=-4:

$\sf -2x+2y=-4$

Subtract 2y from both sides:

$\sf -2x+2y-2y=-4-2y$

$\sf -2x=-4-2y$

Divide both sides by -2:

$\sf \cfrac{-2x}{-2}=-\cfrac{4}{-2}-\cfrac{2y}{-2}$

$\bold{ x=y+2}$

Now, we'll substitute x=y+2 to 3x+3y=-18:

$\sf 3x+3y=-18$

→ let x=2+y

$\sf 3\bold{(2+y)}+3y=-18$

Simplify:

$\sf 6+6y=-18$

Now, let's solve for y in 6+6y=-18

$\sf 6+6y=-18$

Subtract 6 from both sides:

$\sf 6+6y-6=-18-6$

$\sf 6y=-24$

Divide both sides by 6:

$\sf \cfrac{6y}{6}=\cfrac{-24}{6}$

$\bold{ y=-4}$

Now, substitute y=-4 into x=2+y:

$\sf x=2+y$

→ let y = -4

$\sf x=2+\bold{-4}$

$\bold{x=-2}$

Therefore, x=-2 and y=-4.

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5 0

2 years ago

Graph the equation y = 5x Use the graphing tool to graph the line.

taurus [48]

9514 1404 393

Answer:

see attached

Step-by-step explanation:

You want a line that goes through (0, 0) and has a slope of 5. That means it will also go through (1, 5) and (2, 10), for example. I like the attached graphing tool because it will draw the graph directly from the equation.

8 0

3 years ago

g A psychic was tested for extrasensory perception (ESP). The psychic was presented with cards face down and asked to determine

diamong [38]

Answer:

Step-by-step explanation:

Hello!

The objective is to test ESP, for this, a psychic was presented with cards face down and asked to determine if each of the cards was one of four symbols: a star, cross, circle, square.

Be X: number of times the psychic identifies the symbols on the cards correctly is a size n sample.

p the probability that the psychic identified the symbol on the cards correctly

You have to calculate the sample size n to estimate the proportion with a confidence level of 95% and a margin of error of d=0.01

The CI for the population proportion is constructed "sample proportion" ± "margin of error" Symbolically:

p' ± $Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )$

Where $d= Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )$ is the margin of error. As you can see, the formula contains the sample proportion (it is normally symbolized p-hat, in this explanation I'll continue to symbolize it p'), you have to do the following consideration:

Every time the psychic has to identify a card he can make two choices:

"Success" he identifies the card correctly

"Failure" he does not identify the card correctly

If we assume that each symbol has the same probability of being chosen at random P(star)=P(cross)=P(circle)=P(square)= 1/4= 0.25

Let's say, for example, that the card has the star symbol.

The probability of identifying it correctly will be P(success)= P(star)= 1/4= 0.25

And the probability of not identifying it correctly will be P(failure)= P(cross) + P(circle) + P(square)= 1/4 + 1/4 + 1/4= 3/4= 0.75

So for this experiment, we'll assume the "worst case scenario" and use p'= 1/4 as the estimated probability of the psychic identifying the symbol on the card correctly.

The value of Z will be $Z_{1-\alpha /2}= Z_{0.975}= 1.96$