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

12 +15 =710      [12+15];2-310=120
710 ;2 =720
720 - 310 =720 -620 =120
2    34 -512 =912 -512 =412   [  34 -512]x8+118=2 1318
412 х  8 =83=2 23
2 23 +118=2 12 18+118=2 1318