Докажите тождество:
1)-(m-3n)=3n-m
2)7(2-p)+7p=14
3)5a=3(a-4)+2(a+6)
4)4(m-3)+3(m+3)=7m-3

1) -(m-3n)=3n-m

-m+3n=3n-m

-m+3n-3n+m=0

0=0

2) 7(2-p)+7p=14

14-7p+7p=14

14=14

3) 5a=3(a-4)+2(a+6)

5a=3a-12+2a+12

5a=5a

4) 4(m-3)+3(m+3)=7m-3

4m-12+3m+9=7m-3

7m-3+7m-3