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HACTEHA [7]
3 years ago
5

3x + 2y = 5 5x + 2y = 7 Based on the given system of equations, which of the following is not true? 2x = 2 8x = 12 4y = 4

Mathematics
1 answer:
weqwewe [10]3 years ago
6 0
<h3>Answer:</h3>

8x = 12

<h3>Explanation:</h3>

Subtracting the first equation from the second, you get ...

... (5x +2y) -(3x +2y) = (7) -(5)

... 2x = 2 . . . . . the first answer choice is true

___

Multiplying this expression for x by 4, we get

... 8x = 8 . . . . . the second answer choice (8x=12) is false

___

Adding thee first equation to the second, you get ...

... (3x +2y) +(5x +2y) = (5) +(7)

... 8x +4y = 12

... 8 + 4y = 12 . . . . . . use the value of 8x just computed

... 4y = 4 . . . . . . . . . . subtract 8; the third answer choice is true

_____

<em>Alternate approaches</em>

In short, if you solve the system by any of the methods available, you find x=1 and y=1, so the second answer choice is clearly the correct one:

... 8x ≠ 12

By Cramer's method:

... x = (2·7-2·5)/(2·5-2·3) = 4/4 = 1

... y = (5·5-7·3)/4 = 4/4 = 1

By graphing, see attached.

By substitution (for 2y):

... 5x +(5-3x) =7 . . . . . using 2y=5-3x

... 2x = 2 . . . . . . subtract 5

... x = 1 . . . . . . . .divide by 2

... 5 -3·1 = 2y = 2 . . . . substitute x into the expression for 2y

... y = 1 . . . . . . . divide by 2

By matrix methods, see the second attachment. (x, y) = (1, 1), found in the rightmost column of the result.

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X/3/4 = 100<br> what does x equal
Crank

Answer:

x=1200

Step-by-step explanation:

x/3/4=100

Step 1: Multiply both sides by 4.

x/3/4=100

(x/3/4)*(4)=(100)*(4)

x/3=400

Step 2: Multiply both sides by 3.

3*(3/x)=(3)*(400)

x=1200

4 0
3 years ago
Blood type AB is the rarest blood type, occurring in only 4% of the population in the United States. In Australia, only 1.5% of
Naddik [55]

Answer:

There is a 27.62% probability that exactly 2 of the U.S. residents have blood type AB.

Step-by-step explanation:

For each U.S. resident, there are only two outcomes possible. Either they have blood type AB, or they do not. This means that we can solve this problem using binomial probability distribution concepts.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}

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

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

And \pi is the probability of X happening.

In this problem, we have that:

50 U.S residents are sampled, so n = 50

4% of the U.S population has blood type AB, so p = 0.04.

What is the probability that exactly 2 of the U.S. residents have blood type AB?

This is P(X = 2). So:

P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}

P(X = 2) = C_{50,2}.(0.04)^{2}.(0.96)^{48} = 0.2762

There is a 27.62% probability that exactly 2 of the U.S. residents have blood type AB.

5 0
3 years ago
Hey can you help me fast I need to get this grade to a 90 by 12:00 I have an 83 rn.
Nesterboy [21]

Answer:

30/50

Step-by-step explanation:

because there is a y distance of 30 and x distance of 50 from point to point.

3 0
2 years ago
Tlachihualtepeti is a pyramid in mexico. each side of the base measures 450 meters and had an original height of 66 meters. How
storchak [24]

Answer:

Basically, we are to determine the volume of that pyramid.

Right Regular Pyramid Volume = (Area of the Base * Height) ÷ 3

Volume = (202,500  * 66) ÷ 3

Volume = 4,455,000 cubic meters

By the way Wikipedia says that is the largest pyramid in the world.

Step-by-step explanation:

3 0
3 years ago
Solve the equation. Check the solution.<br> 6/7x= - 18
dexar [7]

Answer:

x= -21

Step-by-step explanation:

6/7x=-18

divide both sides by 6/7

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

x= -21

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

8 0
3 years ago
Read 2 more answers
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