How do you solve this<br> I know the answer is x<br> But I want to know how you get to there

Melons cost $20 pet Crate, and apples cost $8 per create. an order comes in for a total of 48 crates for $420. what was the numb

Alika [10]

Answer:

The number of melon was 3 and the number of apples was 45.

Step-by-step explanation:

1. Melons cost $20 per crate and apples cost $8 per create. If the total was 48 crates for $420, you can make the following system of equations, where $x$ is the number of melons and $y$ is the number of apples:

$\left \{ {{x+y=48} \atop {20x+8y=420}} \right.$

2. By applying the Method of substitution, you can solve for $y$ in the first equation and substitute it into the second one to find $x$ . Then, you can substitute the value of $x$ into the first equation to find $y$ :

$y=48-x$

$20x+8(48-x)=420\\20x+384-8x=420\\12x=36\\x=3$

$3+y=48\\y=45$

4 0

3 years ago

If (k-6)(k+2)-(k²-20)=2k+6, whatis tge value of k?

xxMikexx [17]

K=1/3

simplify each bracket, put all numbers on the left hand side, equal it to 0 and solve for k

7 0

2 years ago

Ive been at this for abt 30 min. help?

gregori [183]

Answer:

$1+\frac{-63}{x^2-1}$

Step-by-step explanation:

If you foil this equation you will get:

$\frac{(x+8)(x-8)}{(x+1)(x-1)}$

And by dividing it, you will get;

$1+\frac{-63}{x^2-1}$

That is your answer!

6 0

3 years ago

a math teacher claims that she has developed a review course that increases the score of students on the math portion of a colle

madam [21]

Answer:

A.

$H_0: \mu\leq514\\\\H_1: \mu>514$

B. Z=2.255. P=0.01207.

C. Although it is not big difference, it is an improvement that has evidence. The scores are expected to be higher in average than without the review course.

D. P(z>0.94)=0.1736

Step-by-step explanation:

<em>A. state the null and alternative hypotheses.</em>

The null hypothesis states that the review course has no effect, so the scores are still the same. The alternative hypothesis states that the review course increase the score.

$H_0: \mu\leq514\\\\H_1: \mu>514$

B. test the hypothesis at the a=.10 level of confidence. is a mean math score of 520 significantly higher than 514? find the test statistic, find P-value. is the sample statistic significantly higher?

The test statistic Z can be calculated as

$Z=\frac{M-\mu}{s/\sqrt{N}} =\frac{520-514}{119/\sqrt{2000}}=\frac{6}{2.661}=2.255$

The P-value of z=2.255 is P=0.01207.

The P-value is smaller than the significance level, so the effect is significant. The null hypothesis is rejected.

Then we can conclude that the score of 520 is significantly higher than 514, in this case, specially because the big sample size.

C. do you think that a mean math score of 520 vs 514 will affect the decision of a school admissions adminstrator? in other words does the increase in the score have any practical significance?

Although it is not big difference, it is an improvement that has evidence. The scores are expected to be higher in average than without the review course.

D. test the hypothesis at the a=.10 level of confidence with n=350 students. assume that the sample mean is still 520 and the sample standard deviation is still 119. is a sample mean of 520 significantly more than 514? find test statistic, find p value, is the sample mean statisically significantly higher? what do you conclude about the impact of large samples on the p-value?

In this case, the z-value is

$Z=\frac{520-514}{s/\sqrt{n}} =\frac{6}{119/\sqrt{350}} =\frac{6}{6.36} =0.94\\\\P(z>0.94)=0.1736>\alpha$

In this case, the P-value is greater than the significance level, so there is no evidence that the review course is increasing the scores.

The sample size gives robustness to the results of the sample. A large sample is more representative of the population than a smaller sample. A little difference, as 520 from 514, but in a big sample leads to a more strong evidence of a change in the mean score.

Large samples give more extreme values of z, so P-values that are smaller and therefore tend to be smaller than the significance level.

8 0

3 years ago

Let

kow [346]

Answer:

can write it again soon as you can do it again

6 0

3 years ago

How do you solve this I know the answer is x But I want to know how you get to there