Question

помогите пожалуйста номер 228 заранее спс)

Answer 1

(77³-69³)/(70²-62²)-(77³+41³)/(125²-49)-1/2=
=(77-69)(77²+77*69+69²)/((70-62)(70+62))-
-(77+41)(77²-77*41+41²)/((125+7)*(125-7))-1/2=
=8*(77²+77*69+69²)/(8*132)-118*(77²-77*41+41²)/(132*118)-1/2=
=(77²+77*69+69²)/132-(77²-77*41+41²)/132-1/2=
(77²+77*69+69²-77²+77*41-41²)/132=1/2=
=(110*77+(69²-41²))/132-1/2=(110*77+110*28)/132-1/2=
=110*105/132-1/2=10*105/12-1/2=1050/12-1/2=87,5-0,5=87.

Answer 2

спасибо)

Answer 3

спасибо)