Arithmetic Operator Puzzles

#865: 2 _ 7 _ 7 _ 7 = 15 hard #866: 2 _ 7 _ 7 _ 7 = 13 medium #867: 2 _ 7 _ 8 _ 2 = 18 hard #868: 2 _ 7 _ 8 _ 8 = 15 hard #869: 2 _ 7 _ 8 _ 2 = 10 medium #870: 2 _ 7 _ 8 _ 4 = 12 medium #871: 2 _ 7 _ 8 _ 8 = 13 hard #872: 2 _ 7 _ 9 _ 3 = 17 hard #873: 2 _ 7 _ 9 _ 9 = 15 hard #874: 2 _ 7 _ 9 _ 3 = 11 hard #875: 2 _ 8 _ 2 _ 4 = 6 easy #876: 2 _ 8 _ 2 _ 3 = 14 hard #877: 2 _ 8 _ 2 _ 4 = -2 easy #878: 2 _ 8 _ 2 _ 2 = 17 hard #879: 2 _ 8 _ 2 _ 2 = 15 hard #880: 2 _ 8 _ 2 _ 2 = 1 easy #881: 2 _ 8 _ 2 _ 6 = 3 easy #882: 2 _ 8 _ 3 _ 2 = 14 hard #883: 2 _ 8 _ 3 _ 4 = 8 medium #884: 2 _ 8 _ 3 _ 6 = 6 easy #885: 2 _ 8 _ 3 _ 6 = 18 hard #886: 2 _ 8 _ 3 _ 4 = -4 medium #887: 2 _ 8 _ 3 _ 3 = 17 hard #888: 2 _ 8 _ 3 _ 3 = 15 hard #889: 2 _ 8 _ 3 _ 4 = 12 medium #890: 2 _ 8 _ 3 _ 6 = 8 easy #891: 2 _ 8 _ 4 _ 3 = 8 medium #892: 2 _ 8 _ 4 _ 5 = 12 medium #893: 2 _ 8 _ 4 _ 7 = 16 hard #894: 2 _ 8 _ 4 _ 8 = 18 hard #895: 2 _ 8 _ 4 _ 9 = 20 hard #896: 2 _ 8 _ 4 _ 3 = -4 medium #897: 2 _ 8 _ 4 _ 5 = -8 medium #898: 2 _ 8 _ 4 _ 4 = 17 hard #899: 2 _ 8 _ 4 _ 4 = 15 hard #900: 2 _ 8 _ 4 _ 3 = 12 medium #901: 2 _ 8 _ 4 _ 4 = 1 easy #902: 2 _ 8 _ 4 _ 5 = 20 hard #903: 2 _ 8 _ 4 _ 1 = 2 easy #904: 2 _ 8 _ 4 _ 2 = -1 easy #905: 2 _ 8 _ 4 _ 4 = 5 easy #906: 2 _ 8 _ 4 _ 4 = -3 easy #907: 2 _ 8 _ 4 _ 5 = 6 easy #908: 2 _ 8 _ 4 _ 6 = 7 easy #909: 2 _ 8 _ 4 _ 6 = -5 medium #910: 2 _ 8 _ 4 _ 7 = 8 medium #911: 2 _ 8 _ 4 _ 7 = -6 medium #912: 2 _ 8 _ 4 _ 8 = 9 medium