Matchstick Puzzles

#529: Fix 6-8=15 hard #530: Fix 2+8=9 medium #531: Fix 9+4=12 medium #532: Fix 1+3=18 medium #533: Fix 7-3=2 easy #534: Fix 3+9=11 easy #535: Fix 9-6=9 easy #536: Fix 1+3=70 hard #537: Fix 1+0=10 easy #538: Fix 8-2=1 medium #539: Fix 9+0=15 medium #540: Fix 3+0=71 hard #541: Fix 8-6=3 easy #542: Fix 6+0=8 hard #543: Fix 9+8=16 medium #544: Fix 6+4=19 medium #545: Fix 1+8=0 easy #546: Fix 0-5=4 easy #547: Fix 2+8=0 medium #548: Fix 1-5=8 hard #549: Fix 8-1=9 medium #550: Fix 2+0=8 easy #551: Fix 3+7=19 medium #552: Fix 4-6=9 hard #553: Fix 2+8=6 medium #554: Fix 9+8=18 medium #555: Fix 5+8=74 hard #556: Fix 6-9=75 hard #557: Fix 0+2=6 medium #558: Fix 7-8=75 hard #559: Fix 9+7=7 easy #560: Fix 8+6=76 hard #561: Fix 5+2=4 medium #562: Fix 3+6=12 medium #563: Fix 2+6=2 easy #564: Fix 6-5=8 medium #565: Fix 2+6=1 medium #566: Fix 2+6=11 easy #567: Fix 2-1=2 easy #568: Fix 5+7=5 medium #569: Fix 8-2=8 hard #570: Fix 5-1=8 hard #571: Fix 2-7=3 medium #572: Fix 7-4=71 hard #573: Fix 9+8=0 hard #574: Fix 9+7=13 medium #575: Fix 7-8=9 hard #576: Fix 8-0=6 hard