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dedylja [7]
3 years ago
14

-4.2x=21 what does x mean PLEASE

Mathematics
2 answers:
Ad libitum [116K]3 years ago
7 0

Answer:

X is a variable or a symbol for a number we don't know yet. The variable can be plugged in with any number (a fraction, decimal, etc,). For X, the answer would be 5.


zhenek [66]3 years ago
4 0
X is a number that we don’t know yet
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Write an equation of the line with the given slope and y-intercept. slope: -7 y-intercept: 2​
madreJ [45]

Answer:

y= -7x+2

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
HELP PLEASE WITH EXPLANATION
avanturin [10]
So hmm notice the picture below

that's the 30-60-90 rule, notice your triangle, the bottom-left-angle is a right angle, 90°, the angle atop is 30°, so the angle on the bottom-right has to be 60°, thus is a 30-60-90 triangle, and as you can see on the triangle on the left in the picture, those are the ratios for it

so 8 will be x, what is the longer leg or side in yours then? well, is \bf 8\sqrt{3}


3 0
3 years ago
Given that f(x) =<br> X + 3<br> 2 <br> a) Find f(2)<br> b) Find f'(x)<br> c) Find f"(12)
joja [24]

Answer:

Step-by-step explanation:

Unclear.  Did you mean f(x) = 2^(x + 3)?  If so, the parentheses are mandatory.

Assuming that f(x) = 2^(x + 3) is correct, then:

a) f(2) = 2^(2 + 3) = 2^5 = 32

b) f'(x) = 2^(x + 3)*(x + 3)' = 2^(x + 3)(1) = 2^(x + 3)

c) f"(x) = 2^(x + 3) (same as in (b)), so that:

   f"(12) = 2^15

8 0
3 years ago
This equation shows how the total number of appetizer recipes Emily knows depends on the number of weeks she attends culinary sc
Alexxandr [17]

Answer:

W=2

Step-by-step explanation:

First you have to fill A in as 19 because thats how many culinary recipes that she will need to know

Second you then have to get the variable W by itself so you would subtract 17 from the side that W is on

Once you subtract 17 from one side you have to subtract from the other

So therefore W would =2

7 0
3 years ago
An automobile manufacturer claims that its van has a 31.3 miles/gallon (MPG) rating. An independent testing firm has been contra
Yuliya22 [10]

Answer:

z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}} (1)  

z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82  

p_v =2*P(z  

If we compare the p value and the significance level given \alpha=0.02 we see that p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the true mean is NOT significantly different from 31.3 at 2% of signficance.  

Step-by-step explanation:

Data given and notation  

\bar X=31.1 represent the sample mean

\sigma=1.3 represent the population standard deviation for the sample  

n=140 sample size  

\mu_o =31.3 represent the value that we want to test  

\alpha=0.02 represent the significance level for the hypothesis test.  

z would represent the statistic (variable of interest)  

p_v represent the p value for the test (variable of interest)  

State the null and alternative hypotheses.  

We can assume that we conduct a hypothesis in order to check if the true mean is equal to 31.3 , the system of hypothesis would be:  

Null hypothesis:\mu =31.3  

Alternative hypothesis:\mu \neq 31.3  

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:  

z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}} (1)  

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".  

Calculate the statistic  

We can replace in formula (1) the info given like this:  

z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82  

P-value  

Since is a two-sided test the p value would be:  

p_v =2*P(z  

Conclusion  

If we compare the p value and the significance level given \alpha=0.02 we see that p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the true mean is NOT significantly different from 31.3 at 2% of signficance.  

5 0
3 years ago
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