Error Missing required parameters for [Route: ] [URI: admin/user/update/{id}].

Harap dibantu ya teman teman, saya udah berusaha tapi belum dapet juga solusinya, (awam coding)

ini link error saya

https://flareapp.io/share/353VVgE7

dibawah ini web.php saya yg isi routenya

<?php

/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('/', function () {
    return view('welcome');
});

Auth::routes();

Route::get('/home', 'HomeController@index')->name('home');
Route::prefix('admin')->middleware('auth')->group(function ()
    {
        Route::get('user/index','UserController@index');

        Route::get('user/tambah','UserController@tambah');
        Route::post('user/simpan','UserController@simpan');

        Route::get('user/edit/{id}','UserController@edit');
        Route::put('user/update/{id}','UserController@update');
    }
);

dibawah ini UserController.php saya

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class UserController extends Controller
{
    public function index(Request $request)
    {
        $data['objek']=\App\User::latest()->paginate(10);
        return view('user_index', $data);
    }

    public function tambah()
    {
        $data['objek']=new \App\User();
        $data['action']='UserController@simpan';
        $data['method']='POST';
        $data['nama_tombol']='SIMPAN';
        return view('user_form', $data);
    }

    public function simpan(Request $request)
    {
        $request->validate([
            'name'=>'required|min:2',
            'email'=>'required|email|unique:users,email',
            'password'=>'same:password_confirmation'
        ]);

        $objek=new \App\User();
        $objek->name=$request->name;
        $objek->email=$request->email;
        $objek->password= bcrypt($request->password) ;
        $objek->save();
        //\App\User::create($request->except('password_confirmation'));
        return back()->with('pesan','data sudah disimpan');
    }

    public function edit($id)
    {
        $data['objek']= \App\User::findOrFail($id);
        $data['action']='UserController@update';
        $data['method']='PUT';
        $data['nama_tombol'] ='UPDATE';
        return view('user_form', $data);
    }

    public function update(Request $request, $id)
    {
        $request->validate([
            'name'=>'required|min:2',
            'email'=>'required|email|unique:users,email' . $id,
            'password'=>'same:password_confirmation'
        ]);

        $objek= \App\User::findOrFail($id);
        $objek->name=$request->name;
        $objek->email=$request->email;
        if ($request->password != "")
        {
            $objek->password = bcrypt($request->password);
        }
        $objek->save();
        return redirect('admin/user/index')->with('pesan','data sudah di update');
    }

    public function hapus($id)
    {
        $objek= \App\User::findOrFail($id);
        $objek->delete();
        return back()->with('pesan','data berhasil dihapus');
    }
}