2x + y = 3, -6x - 3y = -9?
It is a linear system of equations in 2 unknowns, x and y.
When we try to solve it,
we solve the 1st equation for y
2x + y = 3
y = 3 - 2x
Substitute in the 2nd equation:
-6x - 3(3 - 2x) = -9
-6x - 9 + 6x = -9
-9 = -9
The x's cancel. When all the letters cancel
out and we are left with a true equation,
there are infinitely many solutions.
It is called a DEPENDENT system.
Edwin
