All categories

3 years ago

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).

You might be interested in

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.

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

90/20 = 4.5 hours

So husband starts at 10am and 4.5 hours form that time is 2.30pm

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:

f(n) = 80*3^n

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.

KE = EPE 
1/2mv^2 = 1/2kx^2 

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

1/2(1200)(13.9)^2 = 1/2k(2.2)^2 

now you do the math to solve for k.
k= 115926/2.42
K= 47903.30

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:

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

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

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

3 0

3 years ago