Math help please. I have a test monday and I really want to nkow how to do these.?

3(n-5)-(6-2n)=4n
3n-15-6+2n=4n
5n-4n=21
n=21

-2(x+6)+3(2x-5)=3(x-4)+10
-2x-12+6x-15=3x-12+10
4x-27=3x-2
4x-3x=-2+27
x=25

13x-3=14x
13x-14x=3
-x=3
x=-3

13x-9+2x-5=12x-1+2x
15x-14=14x-1
15x-14x=-1+14
x=13

7(6+w)=6(2+w)
42+7w=12+6w
7w-6w=12-42
w=30
 
Expand the brackets first
3n-15-6-2n = 4n
Group like terms
n-21 = 4n
-21 = 3n
n= -21/3
n = -7

Expand brackets
-2x-12+6x-15 = 3x-12 + 10
Group like terms
4x -27 = 3x -2
4x = 3x + 25
x = 25

13x-3 = 14x
-3 = x

13x + 9 + 2x-5 = 12x-1+2x
15x +4 = 14x -1
15x = 14x -4
x = -4

n+4 = 3.6
n = -0.4

Remember what you do to one side must also be done to the otherside, you want to get your unknown onto one side, and the numbers on the other till your single unknown = the answer.
 
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