Сравните. α+(β+с)_(α+β)+с. (с+d)-y_(c-y)+d. α-(d+f)_α-d-f. ( (c+d)-y_(d-y)+c.

Question

Сравните. α+(β+с)_(α+β)+с. (с+d)-y_(c-y)+d. α-(d+f)_α-d-f. ( (c+d)-y_(d-y)+c.

Answer 1

A+(b+c)=(a+b)+c; (c+d)-y=(c-y)+d; a-(d+f)=a-d-f; (c+d)-y=(d-y)+c