How do I solve a system of linear equations using the elimination method?

Solving a System of Linear Equations by Elimination

The elimination method is a step-by-step process to solve a system of linear equations. It involves manipulating the equations to eliminate one variable at a time until a solution is found. Here's how you can do it:

  1. Start with your system of linear equations. For example:

    {2x+3y=133x2y=5\begin{cases} 2x + 3y = 13 \\ 3x - 2y = 5 \end{cases}

  2. Choose a variable to eliminate. In this case, let's eliminate yy.

  3. Make the coefficients of the chosen variable the same in both equations. To do this, you might need to multiply one or both equations by a constant. In our example, we'll multiply the first equation by 2 and the second by 3:

    {4x+6y=269x6y=15\begin{cases} 4x + 6y = 26 \\ 9x - 6y = 15 \end{cases}

  4. Add the two equations together to eliminate yy:

    (4x+6y)+(9x6y)=26+15(4x + 6y) + (9x - 6y) = 26 + 15 13x=4113x = 41

  5. Solve for the remaining variable (xx in this case): Divide both sides by the coefficient of xx:

    x=4113x = \frac{41}{13}

  6. Substitute the value of the variable you just solved for back into one of the original equations to find the value of the other variable (yy in this case). Using the first original equation:

    2(4113)+3y=132\left(\frac{41}{13}\right) + 3y = 13 3y=1382133y = 13 - \frac{82}{13} y=113y = \frac{1}{13}

So, the solution to the system of linear equations is x=4113x = \frac{41}{13} and y=113y = \frac{1}{13}.

How do I solve a system of linear equations using the elimination method? — Solve Linear Equations by Elimination | Unlo