(1又4分之3-7/8-7/12)除以(-7/8)除以(-7/8)除以(-1又3/4-7/8-12/7)
=[(1+3/4)-7/8-7/12]÷(-7/8)÷(-7/8)÷[-(1+3/4)-7/8-12/7]
=[7/4-7/8-7/12]*(-8/7)*(-8/7)÷[-7/4-7/8-12/7]
=[42/24-21/24-14/24]*(-8/7)*(-8/7)÷[-98/56-49/56-96/56]
=[7/24]*(8/7)*(8/7)÷[-243/56]
=-[1/3]*(8/7)*[56/243]
=-[1/3]*8*[8/243]
=-64/729