12x2.5x4x12.5
=(2.5x4)x(12.5x8)x1.5
=10x100x1.5 =1500
原式=(2.5×4)×(12.5×4)×3
=10×50×3
=500×3
=1500
=(3X4)X2.5x4x12.5=(2.5x4)X(12.5x4)x3=10x50X3=500x3=1500