3questions:
find value for n if 3n-5 = -8(6+5n)
find value for x if -(1+7x) - 6(-7-x) = 36
find value for x if -3(4x+3)+4(6x+1) = 43

3n-5=-8(6+5n) First distribute -8 to 6 and 5n
3n-5= -48-40n Move variables using opposite operations ,n-terms should be on                         the left
43n-5=-48
43n=-43
43n/43=-43/43 n=-1
-(1+7x)-6(-7-x)=36 There is an invisible -1 in front of the first parenthesis. We know it's here because of the negative sign before the first parenthesis. Distribute -1 to (1+7x) and -6 to (-7-x).
-1-7x+42+x+=36 Now combine x-terms with x-terms and regular numbers with regular numbers. This is called combining like terms.
42-6x=36 Move 42 by substracting 42 from 42 and from 36
-6x=-6 Divide -6x by -6 and -6 by -6
x=1

-3(4x+3)+4(6x+1)=43 Distribute -3 to (4x+3) and -4 to (6x+1)
-12x-9+24x+4=43        Combine like terms(explained above)
24x-5=43                   Add 5 to -5 and to 43
24x=48                      Divide 24x And 48 by 24
x=2