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View Full Version : Choosing values of x to prove 'simplification' isn't true



mook11
05-17-2006, 04:23 PM
I don't understand what is being asked to be done here. I don't recall learning anything like this previously. Any help as to what this is and how it is done would be greatly appreciated.

9. Some students simplify

2x(squared) - 32
--------------------
x - 4

as

2x - 8

Choose values of x to show this is not true. Then simplify it correctly.

Hockeyman
05-17-2006, 04:36 PM
Not entirely sure what you are looking for but in order to solve the problem you must know how to factor 2x^2 - 32. Do you know how to factor?

tkhunny
05-17-2006, 05:12 PM
I don't understand what is being asked to be done here. I don't recall learning anything like this previously. Any help as to what this is and how it is done would be greatly appreciated.

9. Some students simplify

2x(squared) - 32
--------------------
x - 4

as

2x - 8

Choose values of x to show this is not true. Then simplify it correctly.Just pick something. Really, pick anything EXCEPT x=0 or x=4 and just substitute into both expressions. Your task is to see that they are NOT equivalent. When you get a different result for each expression, you will be done with the demonstration.

As far as simplifying correctly, just factor appropriately.