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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".

Q: How do i solve systems of equations by adding or subtracting?

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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

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.

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).

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.

Gaussian elimination is used to solve systems of linear equations.

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

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

by adding, subtracting, dividing, and multiplying.

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

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

because you need maths in your life.. everyone does

solve systems of up to 29 simultaneous equations.

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).

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.

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!

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.

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