Question

Решите пожалуйста:
1. (3x+1)+(-3x² -3x+1)=
2. (a+3b)+(3a-3b)=
3. a² -5ab-b² -(a² +b²)=
4. (x+y-z)-(x-y)+(x-y+z)=

Answer 1

1. (3x+1)+(-3x² -3x+1)=3x+1-3x² -3x+1=

=2-3x²

2. (a+3b)+(3a-3b)=a+3b+3a-3b=4а

3. a² -5ab-b² -(a² +b²)=a² -5ab-b² -a² -b²=

=-5аb-2b²

4. (x+y-z)-(x-y)+(x-y+z)=x+y-z-x+y+x-y+z=

=x+y