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You multiply one equation by some constant, or both equations by different constants, and then add one equation to another (or subtract). Here is an example:

2x + 4y = 30

x + y = 10

Multiplying the second equation by (-2), you get:

2x + 4y = 30

-2x -2y = -20

Now you can add the two equations together, resulting in:

2y = 10

You can solve this for "y"; then you can replace the value you found in any of the original equations to find the corresponding value for "x".

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Q: How do i solve systems of equations by adding or subtracting?
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What are the ways to solve a system of linear equations in two variables?

the substitution method in which you take each variable and you find out the value and then plug it into the original equation.the adding and subtracting method in which you subtract\add equations to take out a variable and you can figure out what the other variable is. then you also substitute that into that into the original variable


Solve linear equations with complex coefficients on both sides?

You would solve them in exactly the same way as you would solve linear equations with real coefficients. Whether you use substitution or elimination for pairs of equations, or matrix algebra for systems of equations depends on your requirements. But the methods remain the same.


How do you work a simultaneous equation?

You cannot work a simultaneous equation. You require a system of equations. How you solve them depends on their nature: two or more linear equations are relatively easy to solve by eliminating variables - one at a time and then substituting these values in the earlier equations. For systems of equations containing non-linear equations it is simpler to substitute for variable expression for one of the variables at the start and working towards the other variable(s).


What is the basic rules to solve equations?

The basic rules to solve equations are to isolate the variable on one side of the equation by performing the same operation on both sides. This includes adding or subtracting the same value, multiplying or dividing by the same value, and applying exponent or logarithm rules if necessary. The goal is to simplify the equation until the variable is alone on one side and the solution can be determined.


What is the use of gaussian elimination in education world situations?

Gaussian elimination is used to solve systems of linear equations.

Related questions

How can you use a graph to solve systems of equations?

You can use a graph to solve systems of equations by plotting the two equations to see where they intersect


How do you solve 3 step equations with parentheses?

just use the PEMDAS system. p-parenthesis e-exponents m-multiplication d-division a-adding s-subtracting


Explain how to solve a whole-number equation?

by adding, subtracting, dividing, and multiplying.


What are the ways to solve a system of linear equations in two variables?

the substitution method in which you take each variable and you find out the value and then plug it into the original equation.the adding and subtracting method in which you subtract\add equations to take out a variable and you can figure out what the other variable is. then you also substitute that into that into the original variable


How can you solve a system of equations?

The answer depends on whether they are linear, non-linear, differential or other types of equations.


Why do you solve systems of equations?

because you need maths in your life.. everyone does


What did ABC computers do?

solve systems of up to 29 simultaneous equations.


How do you work a simultaneous equation?

You cannot work a simultaneous equation. You require a system of equations. How you solve them depends on their nature: two or more linear equations are relatively easy to solve by eliminating variables - one at a time and then substituting these values in the earlier equations. For systems of equations containing non-linear equations it is simpler to substitute for variable expression for one of the variables at the start and working towards the other variable(s).


Solve linear equations with complex coefficients on both sides?

You would solve them in exactly the same way as you would solve linear equations with real coefficients. Whether you use substitution or elimination for pairs of equations, or matrix algebra for systems of equations depends on your requirements. But the methods remain the same.


How do you solve algebra with two variables?

Algebraic equations with two variables will need two equations to be able to solve it. Then, you can solve it with either substitution, adding/subtracting them together, or graphing! Those are the basic steps... For example: An instance of substitution: 2x + 1 = y + 2 x + y = 3 You could isolate y in the second equation to equal y = 3-x. Then in the first equation, substitute y with what it equals to 2x + 1 = 3-x+2 Then you can solve for x!


When you solve a system of linear equations by adding or subtracting what needs to be true about the variable terms in the equations?

I guess you mean, you want to add two equations together. The idea is to do it in such a way that one of the variables disappears from the combined equation. Here is an example:5x - y = 15 2x + 2y = 11 If you add the equations together, no variable will disappear. But if you first multiply the first equation by 2, and then add the resulting equations together, the variable "y" will disappear; this lets you advance with the solution.


How do you solve a fraction problem when you don't have the same denominator?

If you are adding or subtracting unlike fractions, convert them to equivalent fractions with a common denominator.