multinomial theorem(redirected from Quadrinomial expansion)
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The theorem that establishes the rule for forming the terms of the nth power of a sum of numbers in terms of products of powers of those numbers.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.