1. Jun 20, 2009

### harvellt

Im not a math master yet. I'm a physics major in calc. 3 at the moment and I am trying to help a couple friends in college algebra. They both have this conceptual problem of thinking they are "moving" stuff from one side of the equation. It is causing tons of sign mistakes and causing a lot of trouble with radicals and such.
Does anyone have some good examples that show your just doing the same thing to both sides of the equation, or is the best way to do a lot of examples and make the "show all their work'?
Thanks!

2. Jun 21, 2009

### symbolipoint

Your friends in College Algebra studied and should have mastered some important properties of Real Numbers and properties of equality and of inequality part-way into their study of Intermediate Algebra; even possibly before they finished Introductory Algebra. Spend time reteaching your friends the commutative and associative properties for addition and multiplication, the distribution property, the identity properties, and the ...can not remember what you call them... properties of equality and inequality. Also substitution principle. They need to know the properties and to have acquired the associated skills, so maybe you can just reteach them to your friends. You might also give a review of laws of exponents. Pick any book you like to use for teaching (reteaching) these ideas and skills.

Really, if these College Algebra students are having the trouble as you have described, the earned prerequisites for the course are dubious. (Maybe "dubious" is the wrong choice of word.)

3. Jun 21, 2009

### poopcaboose

Of course you are really doing the same thing to both sides. But a short cut is to cancel the operation and do the opposite operation to the other side. This always gives you the right sign and takes less thought and time.

4. Jun 21, 2009

### thrill3rnit3

If that's the case then don't "move" stuff from one side to the other.

Do the inverse operation to BOTH sides.

say x+2=4
x+2-2=4-2 because you are trying to ISOLATE x by itself
which leaves you with x=2