1.
(77³ -69³)/(70² -62²) -(77³+41³)/(125² -7²) -1/2 =
(77 -69)(77² +77*69 +69²)/(70 -62) (70 +62) -
(77+41)(77²-77*41+41²)/(125 -7)(125+7) -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 =(77*69 +77*41+69² -41²)/132 -1/2 =(77*110+28*110)/132 -1/2 =110(77+28)/132 -1/2 =110*105/12*11 -1/2 =
2*5*3*35/2*2*3 -1/2 =5*35/2-1/2 =(175 -1)/2 =87.
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(93 -81)(93² +93*81 +81²)/(57-45)(57+45) -
(93 -67)(93² +93*67 +67²)/(64-38)(64+38) +1/2 =
12(93² +93*81 +81²)/(12*102) -26(93² +93*67 +67²)/(26*102) +1/2 =
(93² +93*81 +81²)/102 -(93² +93*67 +67²)/102 +1/2 =
(93² +93*81 +81² -93² -93*67 -67²)/102 +1/2 =
(93*81 -93*67 +81² -67²)/102 +1/2 =(93(81 -67) +(81 -67)(81 +67))/102 +1/2 =
(93*14 +14*148)/102 +1/2 =14*(93 +148)/102 +1/2 =14*241/102 +1/2 ???