greatest common factor, too many arguments?

[steinmann81]

i'm trying to get the greatest common factor for 21m^7,-18m^6,45m^8,-24m^5. but it gives me too many arguments. i put it in like this: gcd(21m^7,-18m^6,45m^8,-24m^5) if i take the commas out i get too few arguments, what am i doing wrong? thanks, adam

[boozee]

Another elementary question.TI-89 can only give GCD for two
arguments, no more) It's a limitation but c'est la vie.