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3 years ago

Enter the value for x that makes the equation 3x – 5 = 7x - 21 true.

Mathematics

2 answers:

Nitella [24]3 years ago

8 0

Answer:

Step-by-step explanation:

3x-5=7x-21

3x-7x=5-21

-4x=-16 ( divide by -4 both sides)

x= 4

AlexFokin [52]3 years ago

8 0

Answer:4

Step by step solution:

3x-5=7x-21
-5=4x-21
16=4x
x=4

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A small aircraft flies a 2160-mi round trip in a 45 mi/h wind. Find the average rate of speed for the trip if the aircraft can f

jok3333 [9.3K]

9514 1404 393

Answer:

216 mi/h

Step-by-step explanation:

The time for the trip with the wind is ...

(1080 mi)/(225 +45 mi/h) = 4 h

The time for the trip against the wind is ...

(1080 mi)/(225 -45 mi/h) = 6 h

The average speed for the entire round trip is ...

(2160 mi)/(4 +6 h) = 216 mi/h

8 0

3 years ago

nventing is a difficult way to make money. Only 5% of new patents earn a substantial profit. A certain city has just had30 indep

Arlecino [84]

Answer:

$P(X \geq 2) = 1-P(X$

And we can find the individual probabilities using the probability mass function and we got:

$P(X=0) = (30C0) (0.05)^0 (1-0.05)^{30-0} =0.2146$

$P(X=1) = (30C1) (0.05)^1 (1-0.05)^{30-1} = 0.3389$

And replacing we got:

$P(X \geq 2) = 1-P(X$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=30, p=0.05)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

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

Solution to the problem

For this case we want this probability:

$P(X \geq 2)$

And we can use the complement rule and we got:

$P(X \geq 2) = 1-P(X$

And we can find the individual probabilities using the probability mass function and we got:

$P(X=0) = (30C0) (0.05)^0 (1-0.05)^{30-0} =0.2146$

$P(X=1) = (30C1) (0.05)^1 (1-0.05)^{30-1} = 0.3389$

And replacing we got:

$P(X \geq 2) = 1-P(X$

3 0

3 years ago

Mr. Brown purchased tires for his car. The tires were $75 each, including tax, plus $10 for installation. Mr. Brown paid $160 fo

Verizon [17]

Answer:

Step-by-step explanation:

The answer is C because t = 2 so 75x2=150 and 150 + 10= 160.

4 0

3 years ago

Which points have an x-value less than zero?

Zanzabum

Answer:

C, D, J

Step-by-step explanation:

Points to the left of the y-axis have a negative x- value

Points to the right of the y-axis have a positive x- value

Points on the y-axis have an x- value of zero

C(- 4, 5), D(- 9, 9 ), J(- 9, 0) ← are the coordinates of the points

All have a negative x- value

8 0

3 years ago

Round 963 to 1 significant figure.

dedylja [7]

963 would be rounded to become 1000.
This is because 9 is the first non-zero number and so since there are only going to be 1 significant figures, the 9 would round up or down. There is a 6 after the 9, so it rounds up to 10, making it 1000.

7 0

3 years ago