Hide the Quick Launch in SharePoint 2013

Hide the Quick Launch in SharePoint 2013
1.Edit the page
2.Add a web part. Choose Script Editor from the Media and Content Category
3.Choose Edit Snippet
4.Paste below CSS
<style type="text/css">
#sideNavBox {
display: none;
}
#contentBox {
margin-left: 0px;
}
.ms-webpartPage-root {
border-spacing: 5px;
}
.ms-core-tableNoSpace.ms-webpartPage-root > tbody > tr > td > table
{
padding: 5px !important;
border-collapse: collapse;
}
</style>

good one: http://sharepointpromag.com/sharepoint/four-ways-add-or-remove-quick-launch-menu-control