<em>While solving a system of equations, if we get a true statement like 1=1, then there will be "infinitely many solutions" and if we get a false statement like 1=2, then there will be "no solution". </em>
Here the statement is 4=4, <u>which is a true statement</u>.
Try to start by reading the manual it came with. If it didn't come with a manual, then your teacher in school will teach you how to use it for specific commands. Otherwise it's just like using a regular calculator but with the ability to do more things, what do you need to know on it?