1/4×（4.85÷5/18－－3.6＋6.15×3（3/5））＋[5.5－1.75×（1（2/3）＋19/21）]=:b4o9s.G:e/v8[)g(u4k7v4F1Y9W7S3x2F1n6y/s2T*z
算式：提示7Y+k7w,O(|9t1Y9W7S3x2F1n6y/s2T*z