Which method is used to solve simultaneous equations by adding or subtracting to eliminate one variable?

The elimination method is a systematic way to solve simultaneous equations by combining them in such a way that one of the variables is eliminated. This technique involves adding or subtracting the equations to remove one variable, allowing for the straightforward solving of the remaining equation that only contains the other variable. Once one variable is determined, it can be substituted back into one of the original equations to find the value of the other variable.

For example, if you have two equations with two variables, you can manipulate them to align coefficients of one variable, making it possible to eliminate that variable when you add or subtract the equations. This process can significantly simplify the calculations needed to solve the equations.

The other methods listed serve different purposes; the substitution method involves solving for one variable in terms of the other and substituting that expression in the other equation. The graphical method utilizes visual representations of equations on a coordinate system to find their intersection points, indicating their solutions. The iterative method is a numerical procedure that approximates solutions and is generally used for more complex or non-linear equations.