Merge branch 'master' into feature/calculator

Author: RezuanMustafaHasan

src/Calculator.java

@@ -1,6 +1,8 @@
 public class Calculator {
+
     public int add(int a, int b) { return a + b; }
-    public int subtract(int a, int b) { return a = a - b; }
+    public int subtract(int a, int b) { return a - b; }
+
     public int multiply(int a, int b) { return a * b; }
     public int divide(int a, int b) { return a / b; }
 }