Question

можно решение фотографией пж. 400 ответ:39. 401 ответ:-9.

Answer 1

400
(9a*9a-81a²-64c²+8c*8c-8c*81a)/72ac=
=(81a²-81a²-64c²+64c²-648ac)/72ac=
-648ac/72ac=-9
401
(6a*6a-36a²-49c²+7c*7c-36a*7c)/42ac)=
=(36a²-36a²-49c²+49c²-252ac)/42ac=
=-252ac/42ac=-6