linear equation vs equation

linear equation and equation both are nouns.

Word	Noun	Adjective	Verb	Adverb
linear equation	Yes	No	No	No
equation	Yes	No	No	No

As nouns, equation is a hypernym of linear equation; that is, equation is a word with a broader meaning than linear equation:

linear equation (noun)	equation (noun)
a polynomial equation of the first degree	the act of regarding as equal
	a mathematical statement that two expressions are equal
	a state of being essentially equal or equivalent; equally balanced