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In algebra, letters are used to express the general properties of numbers. Representing one number by the letter a and another by the letter b, we can write the equality.
a x b=b x a
or, more shortly, ab=ba.
If no other sign is indicated, the multiplication sign is understood between any two letters written side by side.
To represent numbers letters of the Latin alphabet are generally used.
Letters
The Multiplication Sign
Numbers
Algebraic Language