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kodGreya [7K]
3 years ago
8

Solving x + 3y = 5 and -x - y = -3 by eliminationg.

Mathematics
1 answer:
Marina CMI [18]3 years ago
4 0

Answer:

  (x, y) = (2, 1)

Step-by-step explanation:

The x-coefficients are opposites of each other, so the x variable will be eliminated if the two equations are added.

  (x +3y) +(-x -y) = (5) +(-3)

  2y = 2

  y = 1

Substituting into the first equation gives ...

  x +3(1) = 5

  x = 2 . . . . . . . subtract 3

The solution is (x, y) = (2, 1).

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I leave my family's vacation cabin at 8 a.m. and start driving home at a nice, safe 45 mph. Two hours later, my husband, who alw
Murljashka [212]

Answer:

2:30 pm

Step-by-step explanation:

In two hours (from 10am), she is 45 * 2 = 90 miles from vacation cabin.

From then on her average is still 45 mph and her husband's is 65 mph. So, husband catches her 20 miles (65-45=20) in every hour.

<em>The husband has to catch up 90 miles. How long would it take if he is catching up at 20 miles an hour?</em>

<em>90/20 = 4.5 hours</em>

<em />

<em>So husband starts at 10am and 4.5 hours form that time is 2.30pm</em>

6 0
3 years ago
This is a problem I really need help on please help so I actually have two lol put please help with 7 and 8
grigory [225]

Answer:

7.

f(n) = 80*3^n

8.

f(n) = 4 * 3^(n - 1)

7 0
3 years ago
In a certain Algebra 2 class of 25 students, 13 of them play basketball and 11 of them play baseball. There are 4 students who p
Flauer [41]

Answer:

\frac{4}{5}

Step-by-step explanation:

Given: There are 2 classes of 25 students.

            13 play basketball

            11 play baseball.

            4 play neither of sports.

Lets assume basketball as "a" and baseball as "b".

We know, probablity dependent formula; P(a∪b)= P(a)+P(b)-p(a∩b)

As given total number of student is 25

Now, subtituting the values in the formula.

⇒P(a∪b)= \frac{13}{25} +\frac{11}{25} -\frac{4}{25}

taking LCD as 25 to solve.

⇒P(a∪b)= \frac{13\times 1+11\times 1-4\times 1}{25} = \frac{20}{25}

∴ P(a∪b)= \frac{4}{5}

Hence, the probability that a student chosen randomly from the class plays both basketball and baseball is \frac{4}{5}.

6 0
3 years ago
A 1200 kg car rolling on a horizontal surface has speed v = 50 km/h when it strikes a horizontal coiled spring and is brought to
tangare [24]
When the car is moving, it has Kinetic Energy. As soon as the car entercount with the spring, its Kinetic Energy will transfer to Elastic Potential Energy. 

<span>KE = EPE </span>
<span>1/2mv^2 = 1/2kx^2 </span>

<span>change the speed into m/s </span>
<span>50 km/hr = 13.9 m/s </span>

<span>1/2(1200)(13.9)^2 = 1/2k(2.2)^2 </span>

<span>now you do the math to solve for k.
k= 115926/2.42
K= 47903.30</span>
8 0
3 years ago
Kaitlyn tony and juan served a total of 71 orders Monday at the school cafeteria. Toney served 9 fewer orders than kaitlin. Juan
morpeh [17]

Answer:

<u>Kaitlin served 20 orders, Juan served 40 orders and Tony served 11 orders on Monday at the school cafeteria.</u>

Step-by-step explanation:

1. Let's review the information provided to us to answer the question correctly:

Total of orders server at the school cafeteria by Kaitlin, Tony and Juan = 71

Tony served 9 orders fewer than Kaitlin

Juan served 2 times as many orders as Kaitlin

2. How many orders did each one serve?

For answering this question, we should prepare and write down our equation this way:

x = Number of orders served by Kaitlin

2x = Number of order served by Juan ( 2 times as many orders as Kaitlin)

x - 9 = Number of order served by Tony (9 orders fewer than Kaitlin)

x + 2x + x - 9 = 71

4x = 71 + 9

4x = 80

x = 80/4 = 20

x = 20 ⇒ 2x = 40 ⇒ x - 9 = 11

<u>Kaitlin served 20 orders, Juan served 40 orders and Tony served 11 orders on Monday at the school cafeteria.</u>

3 0
3 years ago
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