它可能是( )。
7×= ×= ×= 2×1= =
×21= 51×= ×25= = ×3=
梯形面积=(上底+下底)×高×
= ××
=
=
387+102= 4.8× = 18.6-5.6= 0.25×39×4=
9.6+0.1= + = 32×125%= ×8+ =