14a-12b-a-b, если a=2/7, b= -5/7

Question

14a-12b-a-b, если a=2/7, b= -5/7

Answer 1

14a - a - 12b - b = 13a - 13b = 13(a - b) ==>

13*(2/7 + 5/7) = 13*7/7 = 13*1 = 13

Ответ
13