Comparing Methods to Solve Systems of Equations

Comparing Methods to Solve Systems of Equations

Elimination

Graphing

Substitution

When ONE of the equations is solved for either x or y.x= or y=

When do I use this method?

When the equations are already in slope-intercept form.

When the equations are in the same order or "lined up".

1. Identify which equation is already solved for x or y
2. Substitute the equivalent expression for that variable into the other equation of the system
3. Perform the necessary operations to solve the equation for the remaining variable

1. Make sure the equations are lined up or "match"
2. Choose a variable to eliminate
3. Determine what number(s) you need to multiply your equation(s) by to eliminate the variable (if needed). Multiply your equation(s).
4. Eliminate one variable by adding or subtracting vertically

1. Identify the slope and y-intercept
2. Graph the y-intercept first
3. Use the slope or rise/run to find other points on the line
4. Make sure both lines are graphed

What are the necessary steps?

After you eliminate a variable and solve for the other variable, substitute the value into either equation to find the other variable's value.

After you substitute and solve for a variable, substitute that value into one of the equations to find the other variable's value.

The point of intersection (where the two lines cross) is your solution.

How do I find the solution?