7/5x- 12=x solution: x=30.

A: It turns out that warehouse B has 30 tons of grain.

(2) If warehouse B stores X tons of grain and warehouse A stores (7/5x) tons of grain:

7/5x- 12=x+ 12 solution: x=60.

A: Warehouse B originally stored 60 tons of grain.

Note: these two questions seem to be the same, but the corresponding relationship is actually different.

(1) After warehouse A shipped out 12 tons, the grain storage capacity of the two warehouses was equal, that is, warehouse A stored 12 tons more grain than warehouse B.

(2) After warehouse A delivers 12 tons to warehouse B, the grain storage of the two warehouses is equal, that is, after warehouse A delivers 12 tons and warehouse B delivers 12 tons, the grain storage of the two warehouses is equal, and warehouse A is 2× 12 = 24 tons more than warehouse B.