[1-(7/15+0.35*17/5）÷17/9]*25/8-11/12*（3/4-0.75）=[1-(7/15+0.07*17）*9/17]*25/8-11/12*0=[1-(7/15*9/17+0.07*17*9/17]*25/8=[1-(6/85+0.63]*25/8=[0.37-6/85]*25/8=[37/100-6/85]*25/8=509/1700*25/8=509/544...