1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sergey [27]
3 years ago
13

Solving systems of elimination

Mathematics
1 answer:
Leokris [45]3 years ago
6 0
To answer by systems of elimination, you add equations together to eliminate variables if they have the same amount of negative variables in one as the positive variables in another.
For example, in number one.

x - y = 11
2x + y = 19

Both equations contain a variable expressed in the same numbers of negative and positive in each of them, one positive y and negative y. This lets us add the equations together.
x + 2x = 3x
 11 + 19 = 30
3x = 30
x = 10

Now that we know that x = 10, we can plug it into the first equation, x - y = 11 to find y.

x - y = 11
10 - y = 11
y = -1 

For the second one,

4x + 8y = 20
-4x + 2y = 30

Negate the x's since there is the same and opposite amount, while adding the rest of the equations together.

8y + 2y = 10y
20 + 30 = 50
10y = 50
y = 5

Plug it into the initial equation to find x

4x + 8(5) = 20
4x + 40 = 20

Subtract 40 from both sides

4x = -20
x = -5

For the third equation,

-6x + 5y = 1
6x +4y = -10

Negate the x's, add the rest together

5y + 4y = 9y
1 - 10 = -9
9y = -9
y = -1

Plug it into the first equation to find x

-6x + 5y = 1
-6x + 5(-1) = 1
-6x - 5 = 1

Add five to both sides

-6x = 6
Divide both sides by negative 6
x = -1

When the problems do not have the same value of opposite versions of current numbers, for example:

3x + 4y = 6
-6x +g = 6

You can multiply an entire equation to get similar numbers of a variable.
For example, you can multiply the first equation entirely by 2 to get the same number of positive x's to the negative x's in the second one, changing it to 6x x 8y = 12.

Hope I helped.

You might be interested in
Give a correct interpretation of a 99% confidence level of 0.328 < μ < 0.486.
stepladder [879]

Answer:

D

Step-by-step explanation:

Lower bound of the population mean is 0.328

Upper bound of the population mean is 0.486

Confidence level is 99%

Therefore, the correct interpolation of the confidence interval is that we are 99% confident that the true value of the population mean is between 0.328 and 0.486

5 0
3 years ago
Miss Miller teaches three times as many students during first hour as she does during third hour. Her
coldgirl [10]
What you would do is multiply 72 and 3 so it says three times so you multiply 72 three times so this would equal 638
8 0
3 years ago
AABC~ ADEF. What is the scale factor?<br><br> Help please
vladimir1956 [14]

Answer:

3:1 or 3

Step-by-step explanation:

the left triangle is scaling up to the right triangle. 5/15 is 1/3

7/21 is 1/3

4/14 is 1/3

since it is scaling UP, the scale factor is 3:1

7 0
3 years ago
Divide: 28.324 : 0.4<br> A 0.7081<br> B 7,081<br> C 708.1<br> D 70.81
valina [46]

Answer:

D-70.81

Step-by-step explanation:

I did the math, this should be correct.

Good luck!

3 0
2 years ago
Read 2 more answers
Which which division problem does the diagram below best illustrate?<br><br><br>60 points ​
siniylev [52]

Answer:

Step-by-step explanation:

32 divide 4 = 8

4 0
3 years ago
Read 2 more answers
Other questions:
  • Which is the solution set of the compound inequality 3.5x-10&gt;-3 and 8x-9&lt;39
    15·2 answers
  • Need help with number 40 plz. I was a little confused when I tried.
    7·1 answer
  • Solve and SHOW YOUR WORK for the equation 3(4x – 2) = 9 + 2x + 5
    9·2 answers
  • Substitution method<br> x= -2y <br> 2x+5y=-1
    10·2 answers
  • What is the area calculation of an orange
    12·1 answer
  • What is the equation of the line that passes through the point (6,14) and is parallel to the line with the following equation? y
    13·1 answer
  • What’s the answer for this
    12·1 answer
  • What is the distributive property of 6(14+7)
    10·1 answer
  • Three friends got the prize money worth 36,000. The first friend would get three times the amount of the third friends portion.
    15·1 answer
  • If arc BC is 42° and angle 5 is 32°, what is the measure of arc DE?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!