(1,75*4/7-1,75:1 1/8)*4,5-4,5 Пожалуйста помогите

$(1,75*\frac{4}{7}-1,75:1\frac{1}{8})*4,5-4,5$ = $(1,75*\frac{4}{7}-1,75:\frac{9}{8})*4,5-4,5$ = $(1,75*\frac{4}{7}-1,75*\frac{8}{9})*4,5-4,5$ = $(1,75*(\frac{4}{7}-\frac{8}{9}))*4,5-4,5$ = $(1\frac{3}{4}*(\frac{36}{63}-\frac{56}{63}))*4,5-4,5$ = $(\frac{7}{4}*(-\frac{20}{63}))*4,5-4,5$ = $(\frac{1}{1}*(-\frac{5}{9}))*4,5-4,5$ = $-\frac{5}{9}*4,5-4,5$ = $-\frac{5}{1}*0,5-4,5$ = $-2,5-4,5$ = $-7.$