Hard Arithmetic Puzzles

#373: 1 _ 8 _ 2 _ 5 = 20 hard #379: 1 _ 8 _ 2 _ 9 = 13 hard #387: 1 _ 8 _ 3 _ 6 = 16 hard #389: 1 _ 8 _ 4 _ 6 = 13 hard #390: 1 _ 8 _ 4 _ 7 = 15 hard #391: 1 _ 8 _ 4 _ 8 = 17 hard #392: 1 _ 8 _ 4 _ 9 = 19 hard #394: 1 _ 8 _ 4 _ 5 = -9 hard #408: 1 _ 8 _ 4 _ 8 = 16 hard #409: 1 _ 8 _ 4 _ 9 = 11 hard #410: 1 _ 8 _ 4 _ 9 = -7 hard #411: 1 _ 8 _ 4 _ 9 = 18 hard #414: 1 _ 8 _ 5 _ 4 = -9 hard #416: 1 _ 8 _ 5 _ 2 = 20 hard #417: 1 _ 8 _ 6 _ 4 = 13 hard #418: 1 _ 8 _ 6 _ 9 = 13 hard #423: 1 _ 8 _ 6 _ 3 = 16 hard #426: 1 _ 8 _ 7 _ 4 = 15 hard #428: 1 _ 8 _ 8 _ 4 = 17 hard #432: 1 _ 8 _ 8 _ 4 = 16 hard #433: 1 _ 8 _ 9 _ 4 = 19 hard #434: 1 _ 8 _ 9 _ 6 = 13 hard #435: 1 _ 8 _ 9 _ 3 = 11 hard #437: 1 _ 8 _ 9 _ 4 = 18 hard #439: 1 _ 9 _ 2 _ 4 = 19 hard #445: 1 _ 9 _ 3 _ 4 = 13 hard #446: 1 _ 9 _ 3 _ 5 = 16 hard #455: 1 _ 9 _ 3 _ 5 = 15 hard #459: 1 _ 9 _ 3 _ 8 = 11 hard #461: 1 _ 9 _ 3 _ 9 = 12 hard #464: 1 _ 9 _ 4 _ 2 = 19 hard #465: 1 _ 9 _ 4 _ 3 = 13 hard #466: 1 _ 9 _ 4 _ 8 = 19 hard #470: 1 _ 9 _ 4 _ 8 = 18 hard #471: 1 _ 9 _ 5 _ 3 = 16 hard #473: 1 _ 9 _ 5 _ 3 = 15 hard #474: 1 _ 9 _ 6 _ 8 = 13 hard #476: 1 _ 9 _ 6 _ 2 = 12 hard #477: 1 _ 9 _ 6 _ 3 = 11 hard #483: 1 _ 9 _ 8 _ 4 = 19 hard #484: 1 _ 9 _ 8 _ 6 = 13 hard #485: 1 _ 9 _ 8 _ 2 = 13 hard #486: 1 _ 9 _ 8 _ 4 = 11 hard #489: 1 _ 9 _ 8 _ 4 = 18 hard #490: 1 _ 9 _ 9 _ 3 = 12 hard #502: 2 _ 2 _ 2 _ 8 = 17 hard #503: 2 _ 2 _ 2 _ 9 = 19 hard #514: 2 _ 2 _ 3 _ 6 = 19 hard