SubjectController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Models\Subject;

class SubjectController extends Controller
{
    public function index(){

    	$subjects = Subject::all();


    	return view('subjects')
    		->with('subjects', $subjects);
    }

    public function add(Request $request) {
    	$subject = new Subject;
    	$subject->name = 'Philosphy'; 
    	$subject->description = 'Study of man psychology';
    	$subject->save();
    }

    public function show($id) {
    	$subject = Subject::find($id);

    	$subject = Subject::where('id', $id)->first();

    	dd($subject->name);
    }

    public function delete($id)
    {
    	Subject::where('id', $id)->delete();
    }
}

web.php

<?php

use Illuminate\Support\Facades\Route;

/*
|--------------------------------------------------------------------------
| 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');
});


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

Route::get('/subjects', 'SubjectController@index');
Route::get('/subjects/add', 'SubjectController@add'); // change from get to post
Route::get('/subjects/{id}', 'SubjectController@show'); 
Route::get('/subjects/{id}/delete', 'SubjectController@delete'); // change from get to delete