Question

(5a-3c)(5a 3c)-(7c-a)(7c a)

Answer 1

Пропущены знаки во 2 и 4 скобке!

(5a-3c)(5a+3c)-(7c-a)(7c+a) = 25a^2-9c^2-49c^2+a^2 = 26a^2 - 58c^2 

Answer 2

(5a-3c)(5a+3c)-(7c-a)(7c+a)=

=25a²-9c²-(49c²-a²)=

=25a²-9c²-49c²+a²=

=-24a²-8c²