A-13/15=13/45 нужно найти a

a = 13/15 - 13/45

To solve this equation, you can find a common denominator for 15 and 45, which is 45. Then, multiply 13/15 by 3/3 and 13/45 by 1/1 to get the same denominator.

a = (13/15) * (3/3) - (13/45) * (1/1)

a = 39/45 - 13/45

a = (39-13)/45

a = 26/45

Ответ: a = 26/45