[(20+452÷4+a÷4)×7-25×80]:3-66+125×8 = 1000
[(20+113 + a : 4) × 7 - 2000] : 3 - 66 + 1000 = 1000
[(133+ a : 4) × 7 - 2000] : 3 - 66 = 1000-1000
[(133 + a : 4) × 7 - 2000] : 3 = 66
(133 + a : 4) × 7 - 2000 = 66 × 3
(133 + a : 4) × 7 = 198 + 2000
(133 + a : 4 ) × 7 = 2 198
133 + a : 4 = 2 198 : 7
133 + a : 4 = 314
a : 4 = 314 - 133
a : 4 = 181
a = 181 × 4
a = 724
