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3 years ago

Solve for the unknown 7(42x)=28(4x)

Mathematics

2 answers:

aalyn [17]3 years ago

4 0

Try to use Mathway if your having trouble solving your equations

ahrayia [7]3 years ago

3 0

7(42x)=28(4x)294x=112xSubtract 112x from both sides.294x−112x=112x−112x182x=0Divide both sides by 182.‌182x182‌=‌0182‌x=0. Hope it helped you if it did help please mark as the brainliest answer

You might be interested in

Solve the linear equation 2x+2/4=189.5

seraphim [82]

Change 2/4 to 1/2
2x+1/2=189.5
Subtract 1/2 from both sides(1/2 = .5)
2x=189
Divide both sides by 2
2x/2 = x
189/2= 94.5
x=94.5

6 0

3 years ago

A bag contains 4 blue marbles and 2 yellow marbles. Two marbles are randomly chosen (the first marble is NOT replaced before dra

VMariaS [17]

Answer:

0.4 = 40% probability that both marbles are blue.

0.0667 = 6.67% probability that both marbles are yellow.

53.33% probability of one blue and then one yellow

If you are told that both selected marbles are the same color, 0.8571 = 85.71% probability that both are blue

Step-by-step explanation:

To solve this question, we need to understand conditional probability(for the final question) and the hypergeometric distribution(for the first three, because the balls are chosen without being replaced).

Hypergeometric distribution:

The probability of x sucesses is given by the following formula:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

In which:

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

What is the probability that both marbles are blue?

4 + 2 = 6 total marbles, which means that $N = 6$

4 blue, which means that $k = 4$

Sample of 2, which means that $n = 2$

This is P(X = 2). So

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

$P(X = 2) = h(2,6,2,4) = \frac{C_{4,2}*C_{2,0}}{C_{6,2}} = 0.4$

0.4 = 40% probability that both marbles are blue

What is the probability that both marbles are yellow?

4 + 2 = 6 total marbles, which means that $N = 6$

2 yellow, which means that $k = 2$

Sample of 2, which means that $n = 2$

This is P(X = 2). So

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

$P(X = 2) = h(2,6,2,2) = \frac{C_{2,2}*C_{4,0}}{C_{6,2}} = 0.0667$

0.0667 = 6.67% probability that both marbles are yellow.

What is the probability of one blue and then one yellow?

Total is 100%.

Can be:

Both blue(40%)

Both yellow(6.67%)

One blue and one yellow(x%). So

40 + 6.67 + x = 100

x = 100 - 46.67

x = 53.33

53.33% probability of one blue and then one yellow.

If you are told that both selected marbles are the same color, what is the probability that both are blue?

Conditional probability.

Event A: Both same color

Event B: Both blue

Probability of both being same color:

Both blue(40%)

Both yellow(6.67%)

This means that $P(A) = 0.4 + 0.0667 = 0.4667$

Probability of both being the same color and blue:

40% probability that both are blue, which means that $P(A \cap B) = 0.4$

Desired probability:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4}{0.4667} = 0.8571$

If you are told that both selected marbles are the same color, 0.8571 = 85.71% probability that both are blue

8 0

3 years ago

Imagine that you have developed a genetic test to detect the dominant allele (A) that cause a rare genetic condition. As with mo

s344n2d4d5 [400]

Answer:

Correct option: (B) 1.495%.

Step-by-step explanation:

Denote the events as follows:

X = the test is positive.

A = a person with the dominant allele

The information given are:

$P(X|A)=1\\P (X|A^{c})=0.005\\P(A)=0.01$

According to the law of total probability the probability of an event A, conditional upon the occurrence of another event B is:

$P(A)=P(A|B)P(B)+P(A|B^{c})P(B^{c})$

Use this law to compute the probability of person having a positive result as follows:

$P(X)=P(X|A)P(A)+P(X|A^{c})P(A^{c})\\=(1\times0.01)+(0.005\times(1-0.01))\\=0.01+0.00495\\=0.01495$

The percentage of positive result is: 0.01495 × 100 = 1.495%.

Thus, the percentage of the population will give a positive test is 1.495%.

4 0

3 years ago

Calculate the length of the unknown side of this right angled triangle

azamat

Answer:

12.04

Step-by-step explanation:

Well to solve for the unknown side "c" we need to use the Pythagorean Theorem formula,

$a^2 + b^2 = c^2$

We already have a and b which are 8 and 9 so we plug them in.

$(8)^2 + (9)^2 = c^2$

64 + 81 = c^2

145 = c^2

c = 12.04 rounded to the nearest hundredth.

Thus,

the unknown side is about 12.04.

Hope this helps :)

8 0

3 years ago

If the sphere shown above has a radius of 14 units then what is the approximate volume of the sphere

oksano4ka [1.4K]

Answer:

About 11494.04

Step-by-step explanation:

There is no sphere shown above but I can still get you the answer:

The formula for the volume of a sphere is $\frac{4}{3} *$ π*r³

Putting in the radius, we get:

$\frac{4}{3}$ *π*14³=

$\frac{4}{3}$ *π*2744=

$\frac{10976}{3}$ *π=

3658.66*π≈11494.04

8 0

3 years ago