1. Movable lines class activity.
Solution of systems of two linear simultaneous equations with two variables.
Movable lines class activity.
Question
Consider two simultaneous linear equations
Solution
k = -4
where k is a real constant.
Find the value of k for which there are infinitely many solutions.
Find the values of k for which there is a unique solution.

2. Geometrical interpretation
Case 1: two lines intersect in a point. This is called a unique solution.
Case 2: Two lines are parallel. There are no solutions.
Case 3: Two lines coincide. There is an infinite number of solutions.