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3 years ago

Substitution with negative numbers Evaluate 2 – (-4) + (-y) where y = 7. Stuck? Watch a video or use a hint.

Mathematics

2 answers:

lina2011 [118]3 years ago

5 0

Answer:

Step-by-step explanation:

Zolol [24]3 years ago

3 0

Answer:

-1

Step-by-step explanation:

2 - (-4) + (-y)

plug in 7 as y

2 - (-4) + (-7)

so you start with the first addition/subtraction (PEMDAS)

also the negative is distributed to the -4 make it positive, a negative and a negative equals a positive, therefore positive 4

2 - (-4) = 6

2 + 4 = 6

then... the equation reads

6 + (-7) = -1

*becareful -7 is "more than/ more negative than" 6 making the answer a negative

Read more about sets at:

brainly.com/question/8053622

#SPJ1

4 0

3 years ago

The serving size for the granola that Wilma likes to eat for breakfast is 1/2 cup. How many servings are there in a box that hol

olchik [2.2K]

The answer Is 64

Hope this helps

3 0

4 years ago

Read 2 more answers

I need help with questions 3 and 4

nlexa [21]

Step-by-step explanation:

$7billion = 5 {e}^{15r} \\ 1.4billion = {e}^{15r} \\ ln(1.4 \: billion) = 15r \\ 21.0597 = 15r \\ r = 1.404$

$4) \\ t = 0 \: y= 200 \\200 = a {e}^{0} \\ a = 200 \\ 800 = 200 {e}^{8k} \\ 4 = {e}^{8k} \\ ln(4) = 8k \\ k = 0.1733$

6 0

2 years ago

6x-10y=-8<br> determine if parallel

Murljashka [212]

Answer: Slope = 1.200/2.000 = 0.600

x-intercept = -4/3 = -1.33333

y-intercept = 4/5 = 0.80000

Step-by-step explanation: 6x−10y=−8

Step 1: Add 10y to both sides.

6x−10y+10y=−8+10y

6x=10y−8

Step 2: Divide both sides by 6.

6x/6=10y-8/6

x=5/3y+-4/3

Slope = 1.200/2.000 = 0.600

x-intercept = -4/3 = -1.33333

y-intercept = 4/5 = 0.80000

5 0

3 years ago

In a random sample of 25 people, the mean commute time to work was 33.9 minutes and the standard deviation was 7.2 minutes. Ass

Phoenix [80]

Answer:

$33.9-1.32\frac{7.2}{\sqrt{25}}=31.999$

$33.9+1.32\frac{7.2}{\sqrt{25}}=35.801$

So on this case the 80% confidence interval would be given by (31.999;35.801)

And the margin of error is given by:

$ME = t_{\alpha/2}\frac{s}{\sqrt{n}}$

And replacing we got:

$ME = 1.32\frac{7.2}{\sqrt{25}} =1.9008$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=33.9$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=7.2 represent the sample standard deviation

n=25 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=25-1=24$

Since the Confidence is 0.80 or 80%, the value of $\alpha=0.2$ and $\alpha/2 =0.1$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.01,24)".And we see that $t_{\alpha/2}=1.32$