20/37X9/29+9/37X17/29=?简算
问题描述:
20/37X9/29+9/37X17/29=?简算
答
20/37X9/29+9/37X17/29
=20/37X9/29+17/37X9/29
=(20/37+17/37)X9/29
=1X9/29
=9/29