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3 years ago

Someone help and please answer it fully

Mathematics

1 answer:

IRINA_888 [86]3 years ago

7 0

Answer:

No, Matt did not solve the equation correctly

Correct Answer: x = 8

Step-by-step explanation:

4(x + 2) = 30

Step 1: Distribute

4x + 2 = 30 $=>$ This is his mistake, he should completely distribute 4

to x and 2

Step 2: Subtract 2 from both sides/Isolate x

4x = 28 $=>$ This part is done correctly, but wrong because of Step 1

Step 3: Divide both sides by 4

x = 7 $=>$ This is correct, but again, he messed up on Step 1

<h3>Let's find the correct answer to this equation:</h3><h3>4(x +2) = 30</h3>

Step 1: Distribute

Remember to distribute 4 to all terms in the parenthesis.

4(x + 2) = 4(x) + 4(2)

= 4x + 8

4x + 8 = 30

Step 2: Subtract 8 from both sides/Isolate x

Move all the terms that do not belong to x to the other side. We can do this by subtracting 8 from both sides $=>$ (opposite operation of adding 8)

4x + 8 = 30

4x = 30 - 8

4x = 32

Step 3: Divide both sides by 4/Isolate x

Now we want x by itself. Since x is being multiplied by 4, we have to use the opposite operation, dividing by 4, to have x on one side by itself

4x = 32

4(x) = 32

x = 32 ÷ 4

x = 8

-Chetan K

You might be interested in

9/4 as a mixed fraction

Serjik [45]

Take 4 divided by 9 using long division =2 whole numbers and 1\4 answer=2 1\4

3 0

4 years ago

Asnwer question in screenshot pls

AlexFokin [52]

<h3>Answers:</h3>

first box = 0
second box = 0
third box = 4
fourth box = -3

It's not a typo that 0 is written twice.

==============================================================

Explanation:

This is considered a step function because it resembles steps or a staircase. The vertical pieces aren't drawn to allow it to remain a function (or else it fails the vertical line test). Also there should be open holes at each left endpoint.

Recall that any horizontal line has a slope of 0 due to the fact that the rise is 0

slope = rise/run

The rise takes care of the vertical change in position. But if the line doesn't go up or down, then rise = 0 leads to slope = 0.

In short, the slope of each horizontal portion is 0. It doesn't matter which sub-section you focus on.

This is why you'll type 0 into the first two boxes.

------------------

As for the remaining two boxes, you'll be looking where the graph is the highest and the lowest to determine the max and min y values respectively.

We see that y peaks at y = 4 at the very top. So you'll type 4 into the third box.

Furthermore, we see that the lowest part of the graph is when y = -3. Therefore, this is the minimum aka smallest y value and you'll type -3 into the fourth box.

7 0

3 years ago

Rothamsted Experimental Station (England) has studied wheat production since 1852. Each year many small plots of equal size but

podryga [215]

Answer:

(a) 0.653

(b) 0.0198

(c) Yes, after testing we conclude that the population variance of annual wheat production for the first plot is larger than that for the second plot.

Step-by-step explanation:

(a) We are give the sample of one year annual production of wheat (in pounds) ;

4.46, 4.21, 4.40, 4.81, 2.81, 2.90, 4.93, 3.54, 4.16, 4.48, 3.26, 4.74, 4.97, 4.02, 4.91, 2.59

For calculating sample variance, firstly we will calculate mean of the above data;

Mean of above data, $X_1bar$ = Sum of all values ÷ n (no. of values)

= $\frac{4.46 + 4.21+4.40+.......+4.91+2.59}{16}$ = 4.074

Sample Variance, $s_1^{2}$ = $\frac{\sum (X-X_1bar)^{2} }{n-1}$ = $\frac{(4.46-4.074)^{2}+(4.21-4.074)^{2}+.........+(4.91-4.074)^{2}+(2.59-4.074)^{2} }{16-1}$ = 0.653

(b) Another sample for annual wheat production (in pounds);

3.89, 3.81, 3.95, 4.07, 4.01, 3.73, 4.02, 3.78, 3.72, 3.96, 3.62, 3.76, 4.02, 3.73, 3.94, 4.03

Mean of above data, $X_2bar$ = Sum of all values ÷ n (no. of values)

= $\frac{3.89+3.81+3.95.......+3.94+4.03}{16}$ = 3.88

Sample Variance, $s_2^{2}$ = $\frac{\sum (X-X_2bar)^{2} }{n-1}$ = $\frac{(3.89-3.88)^{2}+(3.81-3.88)^{2}+.........+(3.94-3.88)^{2}+(4.03-3.88)^{2} }{16-1}$ = 0.0198

(c) Now, we have to test the claim that population variance of annual wheat production for the first plot is larger than that for the second plot i.e.;

Null Hypothesis, $H_0$ : $\sigma_1^{2} = \sigma_2^{2}$ or $H_0$ : $\frac{\sigma_1^{2} }{\sigma_2^{2} } = 1$

Alternate Hypothesis, $H_0$ : $\sigma_1^{2} > \sigma_2^{2}$ or $H_0$ : $\frac{\sigma_1^{2} }{\sigma_2^{2} } > 1$

The test statistics used here is;

$\frac{s_1^{2} }{s_2^{2} }* \frac{\sigma_1^{2} }{\sigma_2^{2}}$ ~ $F_n__1-1_,n_2-1$ where, $n_1 = 16$ and $n_2 =16$

Test Statistics = $\frac{0.653 }{ 0.0198}* 1$ ~ $F_1_5_,_1_5$

= 32.98

Since, we are not provided with any significance level so we assume it to be 5% and at this level, the F table gives critical value of 2.4282.

<em>Since our test statistics is higher than the critical value and it falls in the rejection region so we have sufficient evidence to reject null hypothesis and conclude that the population variance of annual wheat production for the first plot is larger than that for the second plot.</em>

8 0

3 years ago

A boat travels at 12 mph in still water. It can travel 18 miles upstream in the same time that it can travel 24 miles downstream

anastassius [24]

Answer:

The current is 34 mph in still water, I think I could be wrong.

8 0

3 years ago

Solve the equation for x, and enter your answer in the box below.<br> x + (-14) = 5

gtnhenbr [62]

Answer:

x = 19

Step-by-step explanation:

x +(-14)= 5

we start by multiplying the + and the - in the bracket which gives you -

posiyive x negative = negative

x - 14 = 5

the -14 crosses the equal sign and becomes +14

x=5 +14

x = 19

If you need any clarification or more explanation pls do mention a the comment section.

Hope this helps and if it does pls mark as branliest answer thx

6 0

4 years ago

Read 2 more answers