Hard Arithmetic Puzzles

#3213: 7 _ 2 _ 4 _ 5 = 19 hard #3215: 7 _ 2 _ 4 _ 6 = 20 hard #3222: 7 _ 2 _ 6 _ 2 = 19 hard #3223: 7 _ 2 _ 6 _ 4 = 17 hard #3226: 7 _ 2 _ 6 _ 8 = 13 hard #3227: 7 _ 2 _ 7 _ 7 = 15 hard #3232: 7 _ 2 _ 7 _ 8 = 16 hard #3233: 7 _ 2 _ 7 _ 9 = 18 hard #3237: 7 _ 2 _ 8 _ 2 = 18 hard #3238: 7 _ 2 _ 8 _ 4 = 16 hard #3241: 7 _ 2 _ 8 _ 8 = 13 hard #3243: 7 _ 2 _ 8 _ 8 = 20 hard #3244: 7 _ 2 _ 8 _ 9 = 19 hard #3245: 7 _ 2 _ 9 _ 3 = 13 hard #3249: 7 _ 2 _ 9 _ 9 = 15 hard #3250: 7 _ 2 _ 9 _ 9 = 13 hard #3251: 7 _ 3 _ 2 _ 8 = 19 hard #3254: 7 _ 3 _ 2 _ 2 = 20 hard #3257: 7 _ 3 _ 3 _ 3 = 20 hard #3259: 7 _ 3 _ 4 _ 8 = 13 hard #3268: 7 _ 3 _ 6 _ 9 = 14 hard #3270: 7 _ 3 _ 6 _ 3 = 17 hard #3272: 7 _ 3 _ 6 _ 4 = 18 hard #3274: 7 _ 3 _ 6 _ 5 = 19 hard #3278: 7 _ 3 _ 7 _ 7 = 20 hard #3283: 7 _ 3 _ 7 _ 6 = 18 hard #3285: 7 _ 3 _ 8 _ 2 = 19 hard #3286: 7 _ 3 _ 8 _ 4 = 13 hard #3291: 7 _ 3 _ 8 _ 2 = 17 hard #3292: 7 _ 3 _ 8 _ 4 = 19 hard #3297: 7 _ 3 _ 9 _ 9 = 20 hard #3298: 7 _ 3 _ 9 _ 6 = 14 hard #3299: 7 _ 3 _ 9 _ 2 = 19 hard #3300: 7 _ 3 _ 9 _ 5 = 16 hard #3301: 7 _ 3 _ 9 _ 6 = 15 hard #3302: 7 _ 3 _ 9 _ 7 = 14 hard #3304: 7 _ 3 _ 9 _ 8 = 13 hard #3305: 7 _ 3 _ 9 _ 9 = 12 hard #3308: 7 _ 4 _ 2 _ 4 = 15 hard #3309: 7 _ 4 _ 2 _ 5 = 17 hard #3314: 7 _ 4 _ 2 _ 2 = 16 hard #3316: 7 _ 4 _ 2 _ 4 = 18 hard #3318: 7 _ 4 _ 2 _ 5 = 19 hard #3325: 7 _ 4 _ 3 _ 6 = 15 hard #3326: 7 _ 4 _ 3 _ 9 = 19 hard #3331: 7 _ 4 _ 4 _ 2 = 15 hard #3335: 7 _ 4 _ 5 _ 2 = 17 hard #3337: 7 _ 4 _ 6 _ 3 = 15 hard