Gradarius will give a warning sign as "the higlighted expression is invalid" when you enter multiple equations in a single cell.

Gradarius only accepts one equation at a time in a single cell. This is how the input is processed by the system. In general, you can enter two types of mathematical objects into a Gradarius cell, *equations and non-equational expressions *** . **An

__is a mathematical object with an equality sign and an__

*equation*__is any mathematical expression that is not an equation.__

*non-equational expressions*If you are solving an equation, note that the following cells in Gradarius must also include equations and they should follow from the previous ones. If you are using a __ non-equational __ expression, then the following expressions must be equivalent to previous ones. Please take a look at the image below to see the proper approach to solving the same problem given as above.