If a=72
a13=1/2
72*13 =1/2
936 =1/2
Than
a12=72*12=864
a12=a13-a1
a12= 12/26 or 6/13
Why?
Because if 13 times "a" is 1/2 ( which means half of a number)
The full number is twice as much:
a13 times 2 = a26 or 1/1
Than a12 is the 12 part of the whole 26 which means a12 = 12/26
If we simplify 12 dived by 26 is:
6/13
Answer: a12=6/13
