-0,56+(3,8+2,44) = -0,56+ 3,8+ 2,44= 3,8+ 2,44 - 0,56= 6,24- 0,56= 5,68
-3,24-(-4,76-2,9) = -3,24+ 4,76+ 2,9=
4,76+ 2,9- 3,24= 7,66- 3,24= 4,42
2 7/15-(2 2/15-8 1/9)=
2 7/15- 2 2/15+ 8 1/9= 5/15+ 8 1/9=
(5•3)/(15•3) + 8 (1•5)/(9•5)=
15/45+ 8 5/45= 8 20/45= 8 4/9.
Или так
2 7/15- (2 2/15- 8 1/9)=
2 7/15- 2 2/15+ 8 1/9=
5/15+ 8 1/9=
(Сокращаем 5/15 на 5);
1/3+ 8 1/9=
(1•3)/(3•3)+ 8 1/9=
3/9+ 8 1/9= 8 4/9.