3/5 * 7/9 - 3/5 * (7/9 - 5/6)= Нужна помощь! Буду благодарна

Question

3/5 * 7/9 - 3/5 * (7/9 - 5/6)=

Нужна помощь! Буду благодарна

Answer 1

3/5 * 7/9 - 3/5 * (7/9 - 5/6) = 3*7/5*9 - 3/5 * (7*4/9*4 - 5*6/6*6) =
= 21/45 - 3/5 * (28/36 - 30/36) = 21/45 - 3/5 * (- 2/36) = 21/45 + 3/5 * 2/36 =
= 21/45 + 3*2/5*6 = 21/45 + 6/30 = 21*2/45*2 + 6*3/30*3 = 42/90 + 18/90 =
= 60/90 = 6/9 = 2/3