Method 1: Graphing
Graphing is best when the both equations are shown in slope-intercept form. For example:
You can easily graph this system of equations and find the intersecting point. The graph is displayed below. This may not always be the case, however and you may get complicated fractions in your answer. In this case, substitution or elimination may be better.
Method 2: Substitution
Substitution is a good method to solve a system of equations when one of the equations can be rearranged to isolate one variable, or the equation already solves for a variable. This isolated expression can then be substituted into the other equation(s) to create a new equation(s) with only one variable.
For example, consider the system of equations:
Since y is much easier to substitute, we can choose y to substitute into the other equation:
We can then simplify the equation:
Then you can substitute x into the original equation:
Solution:
Substitution can be a useful method when the system involves two or three variables and one equation can be easily rearranged to isolate a variable. However, it can become more difficult or time-consuming when the system involves more variables or when the equations are not solving for a variable or can be easily solved. In these cases, other methods such as elimination is more efficient.
Method 3: Elimination
Elimination is a good method to solve a system of equations when the equations can be added or subtracted in a way that eliminates one of the variables.
For example, consider the system of equations:
We can cancel out the variable y and add the other numerals and variables:
This simplifies to:
We can then solve for y:
Solution:
Once we have the value of x, we can substitute it back into one of the original equations to solve for y.
Although elimination is slightly more complicated, it is the most efficient method out of all of the three methods I have shown here.
Hope this helped you :)
(This took like 30 minutes ;-;)