Medium Arithmetic Puzzles

#4: 1 _ 1 _ 3 _ 9 = -2 medium #10: 1 _ 2 _ 3 _ 9 = 7 medium #12: 1 _ 2 _ 3 _ 9 = -5 medium #17: 1 _ 2 _ 3 _ 8 = 12 medium #36: 1 _ 2 _ 4 _ 8 = 10 medium #37: 1 _ 2 _ 4 _ 8 = -6 medium #42: 1 _ 2 _ 5 _ 6 = 15 medium #50: 1 _ 2 _ 6 _ 5 = 15 medium #53: 1 _ 2 _ 6 _ 7 = 10 medium #54: 1 _ 2 _ 6 _ 8 = 11 medium #55: 1 _ 2 _ 6 _ 8 = -5 medium #57: 1 _ 2 _ 6 _ 9 = -6 medium #65: 1 _ 2 _ 8 _ 3 = 12 medium #66: 1 _ 2 _ 8 _ 4 = 8 medium #68: 1 _ 2 _ 8 _ 5 = 9 medium #71: 1 _ 2 _ 8 _ 7 = 11 medium #73: 1 _ 2 _ 8 _ 8 = 12 medium #74: 1 _ 2 _ 8 _ 8 = -4 medium #76: 1 _ 2 _ 8 _ 9 = -5 medium #77: 1 _ 2 _ 9 _ 3 = 7 medium #79: 1 _ 2 _ 9 _ 3 = -5 medium #80: 1 _ 2 _ 9 _ 6 = -2 medium #87: 1 _ 3 _ 2 _ 8 = 12 medium #95: 1 _ 3 _ 4 _ 8 = -5 medium #98: 1 _ 3 _ 4 _ 9 = 12 medium #118: 1 _ 3 _ 6 _ 7 = 14 medium #119: 1 _ 3 _ 6 _ 8 = -6 medium #124: 1 _ 3 _ 8 _ 4 = -5 medium #131: 1 _ 3 _ 8 _ 2 = 12 medium #143: 1 _ 3 _ 9 _ 4 = 7 medium #144: 1 _ 3 _ 9 _ 4 = 12 medium #145: 1 _ 3 _ 9 _ 5 = -2 medium #147: 1 _ 3 _ 9 _ 6 = 9 medium #148: 1 _ 3 _ 9 _ 6 = -3 medium #149: 1 _ 3 _ 9 _ 7 = 10 medium #151: 1 _ 3 _ 9 _ 8 = -5 medium #153: 1 _ 3 _ 9 _ 9 = -6 medium #172: 1 _ 4 _ 3 _ 9 = 12 medium #188: 1 _ 4 _ 6 _ 9 = -5 medium #193: 1 _ 4 _ 6 _ 8 = 12 medium #196: 1 _ 4 _ 7 _ 8 = 14 medium #201: 1 _ 4 _ 8 _ 2 = 8 medium #210: 1 _ 4 _ 8 _ 6 = 8 medium #211: 1 _ 4 _ 8 _ 6 = -4 medium #212: 1 _ 4 _ 8 _ 6 = 12 medium #213: 1 _ 4 _ 8 _ 7 = 9 medium #214: 1 _ 4 _ 8 _ 7 = -5 medium #215: 1 _ 4 _ 8 _ 7 = 14 medium