Primul exercitiu:
9236-[427+A]+23124=
427+A=23124-9236
427+A=13888
A=13888-427
A=13461
Al doilea exercitiu:
[(20+339:3+A:4)×7-5×400]:3-22×3+125×8=1000
[(20+113+A:4)×7-2000]:3-66+1000=1000
[(133+A:4)×7-2000]:3-66=1
[(133+A:4)×7-2000]:3=67
[(133+A:4)×7-2000]=67×3
[(133+A:4)×7-2000]=201
(133+A:4)×7=2000+201
(133+A:4)×7=2201
133+A:4=2201:7
133+A:4=315
133+A=315:4
133+A=67
A=133-67
A=66