added another testcase for addition of fractions with different denominators and updated code accordingly

src/main/py/fractions.py

@@ -1,4 +1,4 @@
-from src.main.py.more_advanced_calculations import gcd
+from src.main.py.more_advanced_calculations import gcd, lcm
 
 def frac_to_dec(num, denom):
     return num/denom
@@ -10,5 +10,13 @@ def reduceFraction(num, denom):
     return (num, denom)
 
 def addFractions(num1, denom1, num2, denom2):
+    if denom1 != denom2:
+        fractionExpansionFactor = lcm(denom1, denom2)
+        frac1Offset = fractionExpansionFactor / denom1
+        frac2Offset = fractionExpansionFactor /denom2
+        num1 *= frac1Offset
+        denom1 *= frac1Offset
+        num2 *= frac2Offset
+        denom2 *= frac2Offset
     result_num = num1 + num2
     return (result_num, denom1)

src/test/py/test_fractions.py

@@ -21,6 +21,9 @@ class fractions(unittest.TestCase):
     def test_add_fractions_1_by_5_and_2_by_5_should_be_3_by_5(self):
         self.assertEqual(addFractions(1,5,2,5), (3,5))
 
+    def test_add_fractions_1_by_10_and_1_by_5_should_be_3_by_10(self):
+        self.assertEqual(addFractions(1,10,1,5), (3,10))
+
 
 if __name__ == '__main__':
     unittest.main()