# 5.1:  Write a function multiply() that takes one positional argument (an expected integer value)
# and one keyword argument (an optional multiplier called mul=).  Make the default for mul= the
# value 2.  Call as shown.

# your code here


x = multiply(5, mul=3)
print(x)                  # 15

y = multiply(5)
print(y)                  # 10

