The question is, can you help me solve problems like:
5 - 2n = 8n -(-4n) ?© BrainMass Inc. brainmass.com December 24, 2021, 5:15 pm ad1c9bdddf
SOLUTION This solution is FREE courtesy of BrainMass!
In problems like the one you sent me, you basically just want to put all the terms with a variable on one side of the equation, and put all the terms without a variable on the other side. That's the first part of doing these problems. So if we do that to your problem, we get this:
5 - 2n = 8n - (-4n) First, cancel the two negatives.
5 - 2n = 8n + 4n Now you add the two things on the right together
5 - 2n = 12n Now we want to get all the terms that have
an "n" in them on one side. So we'll add
2n to both sides.
5 - 2n + 2n = 12n + 2n Simplify the left and right sides.
5 = 14n
So that's the first part of any problem like this. On one side, we've just got a number, and on the other side we've got stuff involving n.
The only thing left to do is to get rid of the 14. To do that, we divide by 14:
--- = --- Cancel the 14's on the right side.
5/14 = n The answer!!
Here's something that might help you solve equations like this. Did you notice that in the first part of solving this problem, there was a -2n on the left side, and we turned it into a +2n on the right side?
Well, that's the way it always works. If you've got something on one side of the equation and you want to bring it over to the other side, it ends up being the negative of what it was on the first side. So if you had this:
y + 5 = x
you could turn it into this:
y = x - 5.
The same kind of thing works for multiplication and division. If you've got something like this:
5/x = 3
you can turn it into this:
5 = 3x.
When it was on the left side, it was a "divided by x" and when we moved it to the right it became a "times x." But be careful to make sure that when you use this, the WHOLE SIDE needs to be multiplied or divided by the thing you're moving. So this doesn't work:
5/x + 4 = 7
5 + 4 = 7x No!!!!!!!
But this does work:
(5 + y)/n = c
5 + y = nc
Hope this helps!© BrainMass Inc. brainmass.com December 24, 2021, 5:15 pm ad1c9bdddf>