5/8+8/4-69/54+9/4-156/7

5/8+8/4-69/54+9/4-156/7
=5/8+16/8-23/18+18/8-22又2/7
=39/8-23/18-22又2/7

5/8+8/4-69/54+9/4-156/7
=5/8+4又1/4-1又5/18-22又2/7
=-19+5/8+1/4-5/18-2/7
=-19+(315/504)+(126/504)-(140/504)-(144/504)
=-19+157/504
=-18又347/504

解：5/8+8/4-69/54+9/4-156/7
=5/8+16/8+18/8-23/18-156/7
=39/8-23/18-156/7
=(39*18-23*8)/8*18-156/7
=259/4-156/7
=(259*7-156*7)/28
=721/28
=103/4

8739/216