Algebra

[willowsummers]

I know this is going to sound weird, but I feel comfortable with you guys... Is anybody on here good with algebra? This internet course I'm taking is kicking my butt. Any help would be appreciated.

[CourtneyDax]

I'm sorry, but I can't help. My hatred for Algebra is profound really.

[Hellbound Hyperion]

I'm down. What's up?

[willowsummers]

Okay the chapter I'm working on now is solving linear equations with variables on both sides of the equation. Here's one I'm getting stuck on...

6-2y=9-8y+6y
I get the combining terms step...
but I'm not sure if it matters what you subtract or add next... everything I try gets me an answer that doesn't make sense when I check it.

[Hellbound Hyperion]

It doesn't matter what you do first. The goal is to get all the terms onto one side.

Easiest thing to do first is to add 8y and 6y together on the right side.

6-2y = 9-14y

Next, add 2y to both sides to eliminate the 2y on the left:

6 = 9-12y

Now subtract 9 from both sides to negate the 9:

-3 = -12y

Now divide both by -12 to solve for y.

1/4 = y

That's one way to do it, anyway. The goal is to get the variable terms on one side, then solve for them.

[willowsummers]

Okay, I think I see what I was doing wrong. I was dividing -3 by -12 instead of the other way around. Then I tried to add the number together to isolate the variable. I'd like to roll my eyes at the my own self. hehe

And I think one more might solve my issues, if that's okay...

2(x-2)=4x-6-2x

First step:
2x-4=4x-6-2x
Second step
2x-4=2x-6 or 2x-4=6x-6
Third step
2x=2x-10 or 2x=6x-10
Then how do I isolate the variable? or am I just totally backwards? lol I'm so out of practice with math.

[Hellbound Hyperion]

OK, so you got to 2x-4 = 6x-6 (let's just choose that one for example).

Now you should move the terms to one side. That way you don't get into that mess you got into with the third step.

So instead of 2x=6x-10, make it -4 = 4x-6. The rest is cake but I'll leave the rest in spoiler here:

SPOILER: Click to show

So -4 = 4x-6. Now add 6 to each side and we get 2 = 4x. Now divide by 4 and the answer is x = 1/2.

ETA: For future reference, if you DO end up in a mess like the third step you took, backtrack and try something else. There's always a solution, you just sometimes have to try everything imaginable before you get there.

[willowsummers]

Okay thank you so much! I had to do it twice but I got it without having to look at the spoiler. I really appreciate it.

And I like the reference to my mess. hehe It really was.

[Hellbound Hyperion]

Glad to help. Algebra as a whole isn't too bad, just takes lots of practice.

[willowsummers]

And remembering tons of rules which I will eventually get down.

[Hellbound Hyperion]

Oh the rules. Also known as Reasons Why I Don't Miss Algebra Ever.