8/25×9/16+9/25×7/16
问题描述:
8/25×9/16+9/25×7/16
答
8/25×9/16+9/25×7/16
=9/25×8/16+9/25×7/16
=9/25(8/16+7/16)
=9/25x15/16
=27/80