Intro Calculus question/algebra, school me please

[Andrew]

I've been struggling trying to figure out this basic algebra trick that was done.

http://i223.photobucket.com/albums/dd164/kyboshh/2010/2011/20111213-DSC03503-1.jpg

My struggle is understanding how the ^2 moved to the other side and changed the equation.

edit* never mind, the person just made a clerical error,

[out2kayak]

Yep, a clerical error. Here is a bit more step by step with what I came out with:

http://i810.photobucket.com/albums/zz22/out2kayak/IMG.jpg

Basically I started with your second line (can't read the first).

I subtracted both sides to gather like terms (in this case, the dx / dy on one side, everything else on the other).

dx/dy were on both parts of the left side so I simply moved the multiply operation to the left of the parenthesis.

Divide both sides by what is in the parenthesis.

Now, a little cleanup on the right side of the equals sign and done.

Thanks for the moment of math! Do I get a gold star? :D

:cheers:

[WSSix]

Sucks trying to learn something you're struggling with when the person doing the grading doesn't catch an incorrect answer. Joe did it correctly.

[Andrew]

Yes Joe right on the money.

Yes WSSix it does indeed. I'm using a buddies test as a study guide. He got perfect on the question so I'm assuming the prof missed the error or just overlooked the clerical as it was irrelevant to the process. It had me tripped up for a good little bit though. Well enough to try and brush up on my algebra and try and figure out what magic was worked that I was missing. I was thinking factoring or some crazy trick I had never seen before. It's funny how easy it is to overlook the obvious when it's staring you right in the face.

Thanks for the help guys,