3/5×3.7+3.6+6.3×3/5
=3/5×（3.7+6.3）+3.6
=3/5×10+3.6
=6+3.6
=9.6
（3/4×7.2+2.8×0.75）÷1.5
=[3/4×（7.2+2.8）]×2/3
=3/4×2/3×10
=1/2×10
=5
6/11÷（1/2+4/5÷8/15）
=6/11÷（1/2+4/5×15/8）
=6/11÷（1/2+3/2）
=6/11÷2
=3/11
117.4-17.4÷0.4+0÷7.61
=117.4-43.5+0
=73.9
設(shè)：運(yùn)回這批水果原來一共x千克
35%x+35%x+60+1/4x=x
(1-0.25-0.35-0.35)x=60
0.05x=60
x=1200