Ответ: 1 . 6 37/40 ; 2 . x = 7/16 ; 3 . 3 11/45 .

Пошаговое объяснение:

1 . 23 - 1/5 - ( 8 3/4 + 7 1/8 ) =

1) 8 3/4 + 7 1/8 = 8 6/8 + 7 1/8 = 15 7/8 ; 2) 23 - 1/5 = 22 5/5 - 1/5 = 22 4/5 ;

3) 22 4/5 - 15 7/8 = 22 32/40 - 15 35/40 = 21 72/40 - 15 35/40 = 6 37/40 .

2 . 4 4/9 x + 1 = 2 17/18 ; ----> 4 4/9 x = 2 17/18 - 1 ; ----> 4 4/9 x = 1 17/18 ; ---->

-----> x = 1 17/18 : 4 4/9 ; ----> x = 7/16 .

3 . 2 1/3 * 3 1/5 - 8 4/9 : 2 = 7/3 * 16/5 - 76/9 * 1/2 = 112/15 - 38/9 = 146/45 = 3 11/45 .