why these scripts are inactive in mvc4

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ASP

ASP.NET

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MVC4

hi
i put these scripts at the end of body in _Layout.cshtml :

@Scripts.Render("~/bundles/jquery")
@Scripts.Render("~/bundles/jqueryval")
@RenderSection("scripts", required: false)

but in the firebug i see they are inactive . and my validations don't work .