1+4/17*(2+2/3-3/4)+17+11/12*21/17＝1+1/17*(8+8/3-3+11/12*21)+17＝1+1/17*(5+8/3+77/4)+17＝1+1/17*(26+2/3+1/4)+17＝1+1/17*323/12+17＝1+19/12+17＝18+1+7/12＝235/12