Hard Arithmetic Puzzles

#2472: 5 _ 6 _ 8 _ 3 = 20 hard #2477: 5 _ 6 _ 9 _ 6 = 20 hard #2478: 5 _ 6 _ 9 _ 2 = 15 hard #2479: 5 _ 7 _ 2 _ 4 = 19 hard #2481: 5 _ 7 _ 3 _ 6 = 19 hard #2483: 5 _ 7 _ 4 _ 2 = 19 hard #2484: 5 _ 7 _ 4 _ 8 = 19 hard #2486: 5 _ 7 _ 4 _ 8 = -9 hard #2488: 5 _ 7 _ 6 _ 3 = 19 hard #2490: 5 _ 7 _ 8 _ 4 = 19 hard #2491: 5 _ 7 _ 8 _ 4 = -9 hard #2495: 5 _ 8 _ 2 _ 4 = 20 hard #2496: 5 _ 8 _ 2 _ 1 = 19 hard #2497: 5 _ 8 _ 2 _ 2 = 18 hard #2499: 5 _ 8 _ 2 _ 4 = 16 hard #2500: 5 _ 8 _ 2 _ 5 = 15 hard #2501: 5 _ 8 _ 2 _ 6 = 14 hard #2502: 5 _ 8 _ 2 _ 7 = 13 hard #2504: 5 _ 8 _ 2 _ 9 = 11 hard #2505: 5 _ 8 _ 3 _ 2 = 17 hard #2511: 5 _ 8 _ 3 _ 6 = 20 hard #2513: 5 _ 8 _ 4 _ 6 = 17 hard #2514: 5 _ 8 _ 4 _ 7 = 19 hard #2518: 5 _ 8 _ 4 _ 7 = -9 hard #2522: 5 _ 8 _ 4 _ 2 = 20 hard #2523: 5 _ 8 _ 4 _ 3 = 13 hard #2528: 5 _ 8 _ 4 _ 7 = 17 hard #2530: 5 _ 8 _ 4 _ 8 = 18 hard #2532: 5 _ 8 _ 4 _ 9 = 19 hard #2535: 5 _ 8 _ 5 _ 4 = 15 hard #2538: 5 _ 8 _ 6 _ 4 = 17 hard #2540: 5 _ 8 _ 6 _ 9 = 17 hard #2543: 5 _ 8 _ 6 _ 9 = -7 hard #2544: 5 _ 8 _ 6 _ 3 = 20 hard #2545: 5 _ 8 _ 7 _ 4 = 19 hard #2546: 5 _ 8 _ 7 _ 4 = -9 hard #2547: 5 _ 8 _ 9 _ 6 = 17 hard #2548: 5 _ 8 _ 9 _ 6 = -7 hard #2549: 5 _ 9 _ 2 _ 3 = 11 hard #2551: 5 _ 9 _ 2 _ 6 = 15 hard #2552: 5 _ 9 _ 3 _ 2 = 11 hard #2553: 5 _ 9 _ 3 _ 4 = 17 hard #2555: 5 _ 9 _ 3 _ 4 = -7 hard #2556: 5 _ 9 _ 3 _ 1 = 14 hard #2557: 5 _ 9 _ 3 _ 2 = 17 hard #2558: 5 _ 9 _ 3 _ 3 = 18 hard #2559: 5 _ 9 _ 3 _ 3 = 12 hard #2560: 5 _ 9 _ 3 _ 4 = 19 hard