Сложить дроби
a) 5/9 + 2/3
б) 1/12+3/4
в) 1/2 + 3/8
г)17/1000+81/100

Вычесть дроби
а) 11/16 - 3/8
б) 5/6 - 5/12
в) 4/7-8/21
г) 17/30 - 4/15

Спасибо огромное

1) ( 5/9 ) + ( 2/3 ) = ( 5/9) + ( 6/9 ) = 11/9 = 1 ( 2/9 ) ; 2) ( 1/12 ) + ( 3/4 ) = ( 1/12 ) + ( 9/12 ) = 10/12 = 5/6 ; 3) ( 1/2 ) + ( 3/8 ) = ( 4/8 ) + ( 3/8 ) = 7/8 ; 4) ( 17/1000 ) + ( 81/100 ) = ( 17/1000 ) + ( 810/1000 ) = 827/1000 = 0,827 ; 5) ( 11/16 ) - ( 3/8 ) = ( 11/16 ) - ( 6/16 ) = 5/16 ; 6) ( 5/6 ) - ( 5/12 ) = ( 10/12 ) - ( 5/12 ) = 5/12 ; 7) ( 4/7 ) - ( 8/21 ) = ( 12/21 ) - ( 8/21 ) = 4/21 ; 8) ( 17/30 ) - ( 4/15 ) = ( 17/30 ) - ( 8/30 ) = 9/30 = 3/10 = 0,3