Solve systems of linear equations with substitution

The  exercise appears under the Algebra I Math Mission. This exercise practices solving systems of equations where one of the equations is solved for one of the variables.

Types of Problems
There is one type of problem in this exercise:


 * 1) Solve the following system of equations.: This problem presents two equations with the $$x$$ and $$y$$ equations for elimination. The student is expected to use elimination and solve the system of the equation. The answer is to be typed in the text boxes below as an x and a y-coordinate. One of the equations is solved for one of the variables.Solve systems of linear equations with substitution.PNG

Strategies
Knowledge of the elimination method of solving equations will help to perform this exercise accurately and efficiently.
 * 1) Students can replace one of the equations with the sum of the two equations and obtain an equivalent system that has the same solution.
 * If, by doing that, they obtain an equation with a single variable, students will be able to find the solution for that variable. This is called the elimination method.
 * 1) Users can see that the coefficients of the variable $$x$$ have opposite signs in the two equations. By adding the equations, they can eliminate $$x$$ as follows.

Real-life applications

 * 1) Applications include supply and demand lines form business and various other situations where there is information gained from different resources.