Linear algebra is the first kind of algebra that a student is introduced to.
We recognise linear equations because each term is either a constant or the product of a constant and a variable. Note that there are no squares or other powers, an no xy terms or anything like that. These equations can have one or more variables but we are limited to one variable per term.
Although the study of linear equations is extensive and can enter many dimensions, and can involve complex numbers (for example), I am mostly going to restrict myself to work that would be covered in high school (and the first year or so of college/university).
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Zoran V (in private correspondence via YouTube, quoted with permission)
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