Given parameters:
First term of the sequence = x
Second term = x + 2
Third term = x + 4
Sum of the first three terms = 72
Unknown:
First term of the sequence = ?
Solution:
The sum of the first three terms is unknown;
(x) + (x + 2) + (x + 4) = 72
Solve for x;
x + x + 2 + x + 4 = 72
3x + 6 = 72
3x = 72 - 6
3x = 66
x = = 22
The first term of the sequence is 22