48*（6/5+8/5-12/5-16/7）
=48*6/5+48*8/5-48*12/5-48*16/7
=40+30-20-21
=29666.66*7778+333.3*4呢？666.66*7778+333.33*4444 =666.66*7778+333.33*2*2222 =666.66*(7778+2222) =666.66*10000 =6666600