(1/3+1/5)×15=?(1/9+1/3)×27=?(1/6+1/4)×36=?89×7/88=?要简便运算,_数学解答

(1/3+1/5)×15=?(1/9+1/3)×27=?(1/6+1/4)×36=?89×7/88=?要简便运算,

人气：239 ℃　时间：2020-05-10 01:56:45

解答

(1/3+1/5)×15
=1/3×15+1/5×15
=5+3
=8
(1/9+1/3)×27
=1/9×27+1/3×27
=3+9
=12
(1/6+1/4)×36
=1/6×36+1/4×36
=6+9
=15
89×7/88
=(88+1)×7/88
=7+7/88
=7又7/88