十五分之二÷(1.1-四分之三)+七分之二×四分之三
=(2/15)÷(1.1-3/4)+(2/7)×(3/4)
=(2/15)÷(4.4/4-3/4)+(2/7)×(3/4)
=(2/15)÷(1.4/4)+(2/7)×(3/4)
=(2/15)×4/1.4+6/28
=8/21+6/28
=(2/7)×(4/3+3/4)
=(2/7)×(25/12)
=50/84
答:依题意得
2/15÷(1.1-3/4)+2/7×3/4
=2/15÷(22/20-15/20)+
2/7×3/4
=2/15÷7/20+2/7×3/4
=2/15×20/7+2/7×3/4
=2/7×3/4×2
=3/7。