三分之1×2分之五减去二分之一×3分之二用乘法交换律怎么写?

Question

如题所述

Answer 1

1/3×5/2-1/2×2/3
=5/2×1/3-2/3×1/2
=5/6-2/6
=3/6
=1/2
乘以交换律：a×b=b×a