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Definition: subtraction from The Penguin Dictionary of Science

The mathematical operation in which the difference of two numbers, vectors, matrices, polynomials, etc., is found. It is best thought of as the inverse of ➤addition.

Summary Article: subtraction
from The Columbia Encyclopedia

fundamental operation of arithmetic; the inverse of addition. If a and b are real numbers (see number), then the number ab is that number (called the difference) which when added to b (the subtractor) equals a (the subtrahend). In terms of addition the symbol −b is called the additive inverse of b with the property that the sum of a number and its inverse equals 0, or b+(−b)=0. It follows that −(−b)=b. The subtraction of b from a is the same as the addition of a and the inverse of b, or ab=a+(−b); e.g., when a=10 and b=5, then 10−5=10+(−5).

The Columbia Encyclopedia, © Columbia University Press 2018

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