To hide the formula bar, simply select 'Hide Formula Bar' under the 'View' option in the main menu, located near the top of the SpreadsheetLIVE user interface. Once it is hidden, the option will change to 'Show Formula Bar', if you decide that it's preferable to see the formula bar. The formula bar is highlighted below.
Image 1 - The 'Hide Formula Bar' option in the 'View' menu and the formula bar highlighted in the user interface.