How do you solve equations that have a variable on both sides?

Question

example: k=8k+28


example: -30n=-27n-63

modulo_function · Accepted Answer

You can add the same thing to both sides and maintain the equality.

So, when someone says "move it to the other side" what they really mean is add the negative (additive opposite) to both sides.

ex 

k=8k+28

I can add a -k to both sides:

k +(-k) = 8k + (-k) +28

0 = 7k + 28

Of course, you'd really say that I just subtracted k from both sides: it's the same thing.

for you second example, to get all the n on one side you have a choice:
1. you can add 30n to both sides
or
2. you can add 27n to both sides

Either way doesn't change the equality but one is better, in my opinion,  because it gets rid of those 'pesky' minus signs!

M. Abuhelwa · Answer

we take the lower variable to the other side with the different side
and put variables in a side and numbers in the other following changing sign when moving
k = 8k + 28
8k - k = -28
7k = -28
k = -28/7
k = -4

-30n=-27n-63
-27n + 30n = 63
3n = 63
n = 63/3
n = 21

trippykat666 · Answer

k=8k+28
 -28    -28
k-28=8k
-k      -k
-28=7k divide both sides by 7
-4=k

-30n=-27n-63
+63          +63
-30n+63=-27n
+30n       +30n
63=3n divide both sides by 3
21=n

its_ramzi · Answer

Bring it to one side and combine like terms.

k = 8k + 28

If you subtract 8k from both sides you get
-7k = 0 + 28
-7k = 28
k = 28/-7
k = -4

-30n=-27n-63
Get n on one side.
To get rid of it on the right, add 27n.
-3n = 0 - 63
-3n = -63
n = 21

rennie · Answer

-30n=-27n-63

add 27n to 30n

3n=63 divide by 3

63/3=21

anime_girl90 · Answer

When you have a variable on both sides of an equation, you want to put all your terms with the variable on one side of the equation, then isolate it. For k=8k+28, first you subtract 8k from both sides which gives you -7k=28. Then to isolate x you divide each side by -7 which gives you k=-4

J.Bo · Answer

k=8k+28
-7k=28
k=-4
them both are the same variable, so you can subtract then get the solution for the variable.

-30n=-27n-63
-3n=-63
n=21
the same count for this one. the same variable so you can subtract or + and then find the value of the variable.

redhot · Answer

you put all the like terms together

ques= k=8k+28

ans= k-8k=28 bring 8k to other side
        -7k=28 divide bothe sides by -7
        k=-4

Koo D · Answer

-30n=-27n-63
-30n+27n=(-27+27)-63
-3n=-63
-3n/3=-63/-3
n=21

linebackerrebel · Answer

move one over to the other side.

exp.  3x= x+9
         2x= 9
           x= 4.5

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How do you solve equations that have a variable on both sides?

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