Ok i have a system of linear equations, and I am asked to discuss the solution. Here is the equation

1a + 0b - 1c + d = 1

0a + b - c + d = 1

3a + b - 3c + 5d = 6

2a - b - c + 2d = 2

a + b - 2c + landa(d) = 2

Im not sure if I spelled landa correctly, but you know what I mean. It asks to solve the equation for general values of landa. Any help with this is appreciated.