Arithmetic Operator Puzzles

#3121: 6 _ 8 _ 4 _ 6 = 9 medium #3122: 6 _ 8 _ 4 _ 6 = -3 easy #3123: 6 _ 8 _ 4 _ 7 = 10 medium #3124: 6 _ 8 _ 4 _ 7 = -4 medium #3125: 6 _ 8 _ 4 _ 8 = 11 medium #3126: 6 _ 8 _ 4 _ 8 = -5 medium #3127: 6 _ 8 _ 4 _ 9 = -6 medium #3128: 6 _ 8 _ 5 _ 4 = 16 hard #3129: 6 _ 8 _ 5 _ 4 = -4 medium #3130: 6 _ 8 _ 6 _ 3 = 10 medium #3131: 6 _ 8 _ 6 _ 9 = 18 hard #3132: 6 _ 8 _ 6 _ 4 = -6 medium #3133: 6 _ 8 _ 6 _ 3 = 2 easy #3134: 6 _ 8 _ 6 _ 2 = 16 hard #3135: 6 _ 8 _ 6 _ 2 = 4 easy #3136: 6 _ 8 _ 6 _ 4 = 2 easy #3137: 6 _ 8 _ 6 _ 2 = 9 easy #3138: 6 _ 8 _ 7 _ 4 = -8 medium #3139: 6 _ 8 _ 9 _ 6 = 18 hard #3140: 6 _ 8 _ 9 _ 3 = 16 hard #3141: 6 _ 9 _ 2 _ 3 = 12 hard #3142: 6 _ 9 _ 2 _ 8 = 19 hard #3143: 6 _ 9 _ 2 _ 9 = 18 hard #3144: 6 _ 9 _ 2 _ 3 = 4 easy #3145: 6 _ 9 _ 2 _ 6 = 8 easy #3146: 6 _ 9 _ 2 _ 3 = 1 easy #3147: 6 _ 9 _ 2 _ 6 = 2 easy #3148: 6 _ 9 _ 3 _ 2 = 12 hard #3149: 6 _ 9 _ 3 _ 4 = 18 hard #3150: 6 _ 9 _ 3 _ 4 = -6 medium #3151: 6 _ 9 _ 3 _ 5 = -9 hard #3152: 6 _ 9 _ 3 _ 3 = -1 easy #3153: 6 _ 9 _ 3 _ 4 = 6 medium #3154: 6 _ 9 _ 3 _ 5 = -3 medium #3155: 6 _ 9 _ 3 _ 5 = 10 medium #3156: 6 _ 9 _ 3 _ 6 = 8 medium #3157: 6 _ 9 _ 3 _ 6 = -4 medium #3158: 6 _ 9 _ 3 _ 7 = 9 medium #3159: 6 _ 9 _ 3 _ 7 = -5 medium #3160: 6 _ 9 _ 3 _ 7 = 14 hard #3161: 6 _ 9 _ 3 _ 8 = -6 medium #3162: 6 _ 9 _ 3 _ 8 = 16 hard #3163: 6 _ 9 _ 3 _ 9 = 11 hard #3164: 6 _ 9 _ 3 _ 9 = -7 hard #3165: 6 _ 9 _ 4 _ 3 = 18 hard #3166: 6 _ 9 _ 4 _ 6 = 12 hard #3167: 6 _ 9 _ 4 _ 3 = -6 medium #3168: 6 _ 9 _ 4 _ 6 = 16 hard