2315.11 – Equations with No Solution


What value of n, in these three simultaneous equations, will make the three equations have no solution?

nx + y = 1

ny + z = 1

x + nz = 1


Solution

Add the equations:

nx + 7 = 1

ny + = 1

x + nz = 1

nx + y + ny + z + x + nz = 3 \rightarrow (n+1)(x + y + z) = 3.

This can be true unless n = -1: (-1 + 1)(x + y + z) = 0(x + y + z) = 3? Nope.