50/7 - 12/5 - 5/7 × 5/12 - 5/3 /4
= 50/7 - 12/5 - 5/7 × 5/12 - 5/12
= 50/7 - 12/5 - 12/7 × 5/12
= 50/7 - 12/5 - 5/7
= 45/7 - 12/5
= 225/35 - 84/35
= 141/35
5/7-12/5-(5/7)*(5/12)-(5/3)*(1/4)
=5/7*(1-5/12)-12/5-5/12
=(5/7)*(7/12)-12/5-5/12
=5/12-12/5-5/12
=-12/5