很简单(5+7)*8+12/(4-2)=102望采纳~ ((5+7)*8+12)/4 -2=25(5+7)×(8+12)÷(4-2)=120
采用倒推法:(5+7)×8+12÷(4-2)=102
(5+7)×8+12÷(4-2)=102 (5+7)×(8+12)÷(4-2)=120
(5+7)×8+12÷(4-2)=102