To calculate the sum of a and b:
a = 21 + 27 = 48b = 12 + 15 = 27
Therefore, the sum of a and b is:48 + 27 = 75.
To calculate the sum of a and b:
a = 21 + 27 = 48
b = 12 + 15 = 27
Therefore, the sum of a and b is:
48 + 27 = 75.