diff --git a/Week04/functions_burakhan_gultoplar.py b/Week04/functions_burakhan_gultoplar.py
new file mode 100644
index 00000000..dd942947
--- /dev/null
+++ b/Week04/functions_burakhan_gultoplar.py
@@ -0,0 +1,39 @@
+custom_power = lambda x=0, /, e=1: pow(x, e)
+
+def custom_equation(
+    x: int = 0,
+    y: int = 0,
+    /,
+    a: int = 1,
+    b: int = 1,
+    *,
+    c: int = 1
+) -> float:
+    """
+    Computes a custom mathematical equation.
+
+    :param x: positional-only integer, default 0
+    :param y: positional-only integer, default 0
+    :param a: multiplier for x, default 1
+    :param b: multiplier for y, default 1
+    :param c: divisor value, keyword-only, default 1
+    :return: calculated float result
+    """
+
+    for val in (x, y, a, b, c):
+        if not isinstance(val, int):
+            raise TypeError("Parameters must be integers")
+
+    if c == 0:
+        raise ZeroDivisionError("c must not be zero")
+
+    return (a * x + b * y) / c
+
+_counter = 0
+
+def fn_w_counter() -> (int, dict[str, int]):
+    global _counter
+    _counter += 1
+
+    module_name = __name__.split('.')[-1]
+    return _counter, {module_name: _counter}