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08-13-2007, 10:25 PM
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Polynomials, equivalent equations
Why doesn't (x - y)^m = x^m - y^m?
Using the rule that (ab)^n = a^n b^n, I thought that the first equation would be true. I've plugged in some integers, and it's not true, but I don't know why. Thanks.
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Excelsior, BS Finance, pursuing degree Studying: Completed: CLEP: Hum. (67), Hist. of U.S. I (74), Hist. of U.S. II (71), Intro. Psych. (69), Intro. Soc. (72), Soc. Sci. and Hist. (74), Western Civ I (72), Western Civ II (70), Am. Lit. (60), Intro. to Educ. Psych. (62), P. of Management (74), P. of Market. (74), Intro. Bus. Law (67), P. of Accounting (60), AmGov (68) DSST: Ethics in Am. (76), P. of Super.(67), HRM (65), Intro to Bus. (70), MIS (65), P. of Fin (62), M&B (65), P. of Stat. (68) ECE: OB (B) Total Credits: 108     
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08-14-2007, 01:30 AM
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i don't know the "textbook reason" but from what i know about polynomials, your equation doesn't equal because (x - y) is different from (ab) so you can't use that rule. for instance, try substituting the variable "m" with a number (let's say 2). so it would be:
(assume m=2) (x - y)^2 = (x - y)(x - y) if you calculated it, it would come out to be x^2 - 2xy + y^2 so if you switch back to using the variable, it would be: x^m - mxy + y^m do you kinda see how that equation works? i'm sorry i don't know a textbook answer =(
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Linear Mode
