LINQ complex delete and search query

//assume that I have the following XML file.

<warehouse>
          <cat id="computer">
            <item>
              <SN>1</SN>
              <name>Toshiba</name>
              <quantity>12</quantity>
              <description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
              <price>400 USD</price>
            </item>
<item>
              <SN>22</SN>
              <name>Toshiba</name>
              <quantity>12</quantity>
              <description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
              <price>400 USD</price>
            </item>
          </cat>
          <cat id="Stationery">
            <item>
              <SN> 33 </SN>
              <name>note books</name>
              <quantity>250</quantity>
              <description>Caterpiller</description>
              <price>5 USD</price>
            </item>
        </cat>
        <cat id="Furniture">
            <item>
              <SN> 1 </SN>
              <name>dasd</name>
              <quantity>asdasd</quantity>
              <description>das</description>
              <price>dasd</price>
            </item>
<item>
              <SN>44</SN>
              <name>Toshiba</name>
              <quantity>12</quantity>
              <description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
              <price>400 USD</price>
            </item>

            <item> 
        </cat>
        </warehouse>

question 1 : I want to Delete <item> element and its child's using linq , where <cat id="computer"> and <SN> has a specific value like 44 .

question 2 : I want to make a query using TextBox and Literal1 which return a specic <item> and its child's . this query should be in linq.