Comparison-Substitution

Grade 10 Math Systems of Equations Elimination Level 1


 * Solving systems of equations using algebra - comparison/substitution**

For two equations: y=3x+1 and y=x-4

It is possible to find the point of intersection by using algebra. At the point of intersection, the two y-values are the same (or equal). Therefore the other sides of the two equations must also be equal to each other, resulting in the equation:

3x+1 = x-4

This equation can be solved to determine x. The value of x can then be substituted into one of the equations to determine y.

Once the value of x and y have been determined, it is a good idea to check the values in the other equation.

Altogether, the steps look like this: 1. Label the two equations. 2. Compare the two equations. 3. Solve for x 4. Solve for y in one of the equations 5. Check the solution in the other equation. 6. State the solution.