why dont compile?

Hi, i´m tryng to compile this example code but arduino give me some errors.

the code is here

#include <Ethernet.h>
#include <SPI.h>

byte mac[] = {0x90,0xA2,0xDA,0x0D,0x00,0xCF};
byte ip[] = {192,168,1,11};
EthernetServer server(80);

int PinLed = 2;
String readString = String(30);

void setup()
{
  Ethernet.begin(mac, ip);
  pinMode(PinLed,OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  EthernetClient client = server.available();
  
  if(client)
  {
    while (client.connected())
    {
      if(client.available())
      {
        char c = client.read();
        
        if(readString.length()<30)
        {
          readString += c;
          Serial.print(c);
        }
        
        if(c=='\n')
        {
          if(readString.trim() ==("GET /?Led=On HTTP/1.1"))   //line 38
          {
          digitalWrite(PinLed,HIGH);
          }
          if(readString.trim()==("GET /?Led=Off HTTP/1.1"))  //line 42
          {
          digitalWrite(PinLed,LOW);
          }
        
          readString="";
          
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println();
          
          client.println("<html>");
          client.println("<head>");
          client.println("<title>Encendido led</title>");   //line 55
          client.println("</head">);
          client.println("<body>");
          client.println("<h1>encendido led por intenrnet</h1>");
          client.println("<form method=get>");
          client.println("<input type=submit name=Led value=On>");
          client.println("<input type=submit name=Led value=Off>");
          client.println("</form>");
          client.println("</body>");
          client.println("</html>");
          
          client.stop();
        }
      }
    }
  }
}

and this is the error log

ethernet_ejemplo.cpp: In function 'void loop()':
ethernet_ejemplo:37: error: void value not ignored as it ought to be
ethernet_ejemplo:41: error: void value not ignored as it ought to be
ethernet_ejemplo:55: error: expected primary-expression before ')' token

can anybody explain me the errors? thanks a lot

          if(readString.trim() ==("GET /?Led=On HTTP/1.1"))   //line 38

What is this supposed to be doing? The trim() method modifies the object it is called for. It does not return a new string.

Quit trying to take so many (illegal) shortcuts.