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3 years ago

The equation for this question.

1 answer:

8 0

We can solve this by setting up a system of equations. We will use x for the $3 boxes and y for the $5 boxes:

x+y=34
3x+5y=130

We can use the elimination method by multiplying the first equation by 3:

3x+3y=102
3x+5y=130

0x-2y=-28
y=14

We can then plug this number back into one of the original equations to solve for x:

x+14=34
x=20

We can check these answers by plugging them into the equations:

20+14=34
34=34

(3)(20)+(5)(14)=130
60+70=130
130=130

Therefore, there are 20 of the $3 boxes, since we originally said that x would be the $3 boxes.

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What is the value of x in the equation below?

mariarad [96]

Answer:

X=2

Step-by-step explanation:

Using distributive property: 1/3(12x-24)=16

4x- 8=16

Using oposite oporations on both sides:

4x-8=16

4x+8=16-8

4x=8

8/4=2

x=2

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3 years ago

Read 2 more answers

1.Show that the statement p: “If x is a real number such that x3 + 4x = 0, then x is 0” is true by

Genrish500 [490]

If x is a real number such that x3 + 4x = 0 then x is 0”.Let q: x is a real number such that x3 + 4x = 0 r: x is 0.i To show that statement p is true we assume that q is true and then show that r is true.Therefore let statement q be true.∴ x2 + 4x = 0 x x2 + 4 = 0⇒ x = 0 or x2+ 4 = 0However since x is real it is 0.Thus statement r is true.Therefore the given statement is true.ii To show statement p to be true by contradiction we assume that p is not true.Let x be a real number such that x3 + 4x = 0 and let x is not 0.Therefore x3 + 4x = 0 x x2+ 4 = 0 x = 0 or x2 + 4 = 0 x = 0 orx2 = – 4However x is real. Therefore x = 0 which is a contradiction since we have assumed that x is not 0.Thus the given statement p is true.iii To prove statement p to be true by contrapositive method we assume that r is false and prove that q must be false.Here r is false implies that it is required to consider the negation of statement r.This obtains the following statement.∼r: x is not 0.It can be seen that x2 + 4 will always be positive.x ≠ 0 implies that the product of any positive real number with x is not zero.Let us consider the product of x with x2 + 4.∴ x x2 + 4 ≠ 0⇒ x3 + 4x ≠ 0This shows that statement q is not true.Thus it has been proved that∼r ⇒∼qTherefore the given statement p is true.

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3 years ago

A study of the amount of time it takes a mechanic to rebuild the transmission for a 1992 Chevrolet Cavalier shows that the mean

Dovator [93]

Answer:

B) 0.0069

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

$\mu = 8.4, \sigma = 1.8, n = 40, s = \frac{1.8}{\sqrt{40}} = 0.2846$

Find the probability that their mean rebuild time exceeds 9.1 hours.

This is 1 subtracted by the pvalue of Z when X = 9.1. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{9.1 - 8.4}{0.2846}$

$Z = 2.46$

$Z = 2.46$ has a pvalue of 0.9931

1 - 0.9931 = 0.0069

So the answer is B.

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3 years ago

What is 1/2 times 5/4?

Katen [24]

Answer:

1 x 5 = 5

2 x 4 = 8

5/8 is the answer.

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3 years ago

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A 4-pack of greeting cards costs $7.40. What is the unit price?pls answer fast

densk [106]

Answer:

The unit price of the problem is that one pack of greeting cards costs $1.85

Step-by-step explanation:

In order to find the unit rate, you have to divide the price by the quantity of the product. So, we will divide 7.40 by 4 so we can see the price of one pack.

7.40 ÷ 4 = 1.85

So, one pack of greeting cards costs $1.85 which is also our unit price.

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