№1.
а) ( 11/12 - 0,75) + 1/16 = (11/12 - 3/4) + 1/16 =
= (11/12 - 9/12) + 1/16 = 2/12 + 1/16 =
= 1/6 + 1/16 = 8/48 + 3/48 = 11/48
б) 7 - 4 3/4 - 1 2/3 = 2 1/4 - 1 2/3=
= 2 3/12 - 1 8/12= 7/12
№2.
6 1/6 - (х+0,375) = 3 7/24
х + 0,375 = 6 1/6 - 3 7/24
х + 0,375 = 6 4/24 - 3 7/24
х + 0,375 = 2 21/24
х + 0,375= 2,875
х=2,875 - 0,375
х= 2,5
проверим:
6 1/6 - ( 2,5 +0,375) = 3 7/24
6 1/6 - 2,875 = 3 7/24
6 1/6 - 2 7/8 = 3 7/24
6 8/48 - 2 42/48 = 3 7/24
3 14/48 = 3 7/24
3 7/24 = 3 7/24
б)
8 1/4 - (х - 3 5/9 ) = 2 7/12
8 1/4 - х + 3 5/9 = 2 7/12
8 9/36 - х + 3 20/36 = 2 7/12
11 29/36 - х= 2 7/12
х= 11 29/36 - 2 7/12 = 11 29/36 - 2 21/36= 9 8/36
х= 9 2/9
проверим:
8 1/4 - ( 9 2/9 - 3 5/9 ) = 2 7/12
8 1/4 - 5 6/9 = 2 7/12
8 1/4 - 5 2/3 = 2 7/12
8 3/12 - 5 8/12 = 2 7/12
2 7/12 = 2 7/12