(1/2+1/5):2-3/10; (3/4-5/12)*8+1/18; (7/15+4/5):3-1/9; (3/7-1/21)*4-1/6

Question

(1/2+1/5):2-3/10;
(3/4-5/12)*8+1/18;
(7/15+4/5):3-1/9;
(3/7-1/21)*4-1/6

Answer 1

1\2 +1\5 =7\10      [1\2+1\5];2-3\10=1\20
7\10 ;2 =7\20
7\20 - 3\10 =7\20 -6\20 =1\20
2    3\4 -5\12 =9\12 -5\12 =4\12   [  3\4 -5\12]x8+1\18=2 13\18
4\12 х  8 =8\3=2 2\3
2 2\3 +1\18=2 12\ 18+1\18=2 13\18