Ответ: 2a/9 - 5b/2 - 6
Пошаговое объяснение:
1/9(2a-18)-1/2(5b+8) = 1/9 *2a/1 - 1/9*18/1 - 1/2 *5b/1 - 1/2 * 8/1 =
= 1*2a/9*1 - 1*18/9*1 - 1*5b/2*1 - 1/8/2*1 = 2a/9 -18/9 - 5b/2 - 8/2 =
= 2a/9 - 2*9/9 - 5b/2 - 4*2/2 = 2a/9 -2 - 5b/2 - 4 = 2a/9 - 5b/2 - 6