diff --git "a/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/python/majinka10.py" "b/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/python/majinka10.py"
new file mode 100644
index 0000000000..d68431abe2
--- /dev/null
+++ "b/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/python/majinka10.py"	
@@ -0,0 +1,15 @@
+import re
+
+patron = re.compile(r'-?\d+(\.\d+)?\s*[+\-*/%]\s*-?\d+(\.\d+)?(?:\s*[+\-*/%]\s*-?\d+(\.\d+)?)?')
+
+def evaluador(expresion:str):
+	match = patron.search(expresion)
+	if match:
+		return True 
+	else:
+		return False
+    
+
+print(evaluador('5 + 6 / 7 - 4'))
+print(evaluador('5 a 3'))
+print(evaluador('3.2 % 3 + 5 - 3 / 2'))
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diff --git "a/Retos/Reto #29 - EL CAR\303\201CTER INFILTRADO [F\303\241cil]/python/majinka10.py" "b/Retos/Reto #29 - EL CAR\303\201CTER INFILTRADO [F\303\241cil]/python/majinka10.py"
new file mode 100644
index 0000000000..37c4a3f113
--- /dev/null
+++ "b/Retos/Reto #29 - EL CAR\303\201CTER INFILTRADO [F\303\241cil]/python/majinka10.py"	
@@ -0,0 +1,13 @@
+def infiltrado(texto1:str,texto2:str):
+    infiltrados=[]
+    if len(texto1) == len(texto2):
+      for tupla in zip(texto1,texto2):
+          if tupla[0] != tupla[1]:
+              infiltrados.append(tupla[0])
+    else:
+        return print('Los textos no tienen el mismo tamaño')
+    return print(infiltrados)
+
+infiltrado('abc','abdc')
+infiltrado('Me llamo mouredev','Me llemo mouredov')
+infiltrado('Me llamo.Brais Moure','Me llamo brais moure')
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diff --git a/Retos/Reto #30 - EL TECLADO T9 [Media]/python/majinka10.py b/Retos/Reto #30 - EL TECLADO T9 [Media]/python/majinka10.py
new file mode 100644
index 0000000000..a7459de500
--- /dev/null
+++ b/Retos/Reto #30 - EL TECLADO T9 [Media]/python/majinka10.py	
@@ -0,0 +1,13 @@
+t9_dict={'1':',','11':'.','111':'?','1111':'!','2':'A','22':'B','222':'C','3':'D','33':'E','333':'F','4':'G','44':'H','444':'I','5':'J','55':'K','555':'L','6':'M','66':'N','666':'O','7':'P','77':'Q','777':'R','7777':'S','8':'T','88':'U','888':'V','9':'W','99':'X','999':'Y','9999':'Z','0':' '}
+
+def convert_to_t9(texto:str):
+    texto=texto.split('-')
+    text_t9=''
+    for bloque in texto:
+        if bloque in t9_dict:
+          text_t9+=t9_dict[bloque]  
+        else:
+           return print('Bloque de números no encontrado')
+    return print(text_t9)
+
+convert_to_t9('44-666-555-2-0-555-444-66-3-88-777-2-1111')
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