Prove system has more than one solution then it has infinite solution

This statment only works for linear systems because in non-linear systems it is okay to have more than one soultion
but if the system is linear than you can define it by it two soultions or in other words it takes two points to form a line and if two lines pass through the same points then you can define them by those point and they are the same line

Just turn the whole gym into pie