Yes, you can. You can manually rewrite any expression by using the "Rewrite" action. Bring the mouse cursor on the equality sign and select “Rewrite”.
It is highly recommended that you use built-in mathematical actions* in your solution whenever is possible.
By doing this you let the system know your logic and your solution can be analyzed by Gradarius more accurately.
* To find the appropriate action, use the blue eye icon located on the upper right side of "actions search box". Once you select a mathematical expression you want to apply an action on, click on the blue eye icon to see all the applicable actions to pick from.