求12.5x0.25x3.2和12.5x4.5+4.5x12.5+12.5的简便计算 快明天就没用了!

求12.5x0.25x3.2和12.5x4.5+4.5x12.5+12.5的简便计算 快明天就没用了!
求12.5x0.25x3.2和12.5x4.5+4.5x12.5+12.5的简便计算 快明天就没用了!

求12.5x0.25x3.2和12.5x4.5+4.5x12.5+12.5的简便计算 快明天就没用了!
12.5×0.25×3.2
=12.5×0.25×4×0.8
=(12.5×0.8)×(0.25×4)
=10×1
=10
12.5×4.5+4.5×12.5+12.5
=12.5×(4.5+4.5+1)
=12.5×10
=125