Выполните действия:1. (7x²–5x+3)–(7x²–5)=2. (3x+1)+(–3x²–3x+1)=3. (a+3b)+(3a–3b)=4. a⁴–5ab–b²–(a²+b²)=5. (x+y–z)–(x–y)+(x–y+z)=

Выполните действия: 1. (7x²–5x+3)–(7x²–5)= 2. (3x+1)+(–3x²–3x+1)= 3. (a+3b)+(3a–3b)= 4. a⁴–5ab–b²–(a²+b²)= 5. (x+y–z)–(x–y)+(x–y+z)=