Here is how I think you can solve your problem:
Open the Workbook. Select sheet  1. Click View on the menu bar,
Toolbars, Visual Basic. After toolbars shows, click Visual Basic
Editor icon. In the VBA window on the left side select Sheet 1 and
click View Code icon. In the Code window edit or paste the following
code:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)

Sheets("Foaie2").Rows("9:60").Hidden = False
Sheets("Foaie3").Rows("9:60").Hidden = False

End Sub

Or, in the Sheet 1 in cell  A1 (or in other which is not used)
enter the formula: =B17 and in the VBA code window edit the
following code:

Private Sub Worksheet_Calculate()

Sheets("Foaie2").Rows("9:60").Hidden = False
Sheets("Foaie3").Rows("9:60").Hidden = False
End Sub

This code runs properly, but depending on what else exist on the
Sheet 1, a few other conditions (If…Then…End) must be added, in
order that these instructions run  only when you want (when you enter
a number  in cell B17) and not at other operations in the Sheet 1.
I'll be glad to hear that it worked and in case you need to edit the
conditions (If…Then…End) send a detailed mail on the following
address: dorelbaiu@....