исправление ошибок

app/Models/AcademicPlan.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class AcademicPlan extends Model
+{
+    use HasFactory;
+
+    protected $primaryKey = ['subject_id', 'class_id'];
+
+    public $incrementing = false;
+}

app/Models/SchoolClass.php

@@ -19,4 +19,10 @@ class SchoolClass extends Model
     {
         return $this->hasMany(Student::class);
     }
+
+    public function subjects()
+    {
+        return $this->belongsToMany(Subject::class, 'academic_plans')->withPivot('hours_per_week', 'hours_per_year');
+    }
+
 }

app/Models/Subject.php

@@ -17,4 +17,10 @@ class Subject extends Model
     {
         return $this->hasMany(BankTask::class);
     }
+
+    public function schoolClasses()
+    {
+        return $this->belongsToMany(SchoolClass::class, 'academic_plans')->withPivot('hours_per_week', 'hours_per_year');
+    }
+
 }