Answer:
Step-by-step explanation:
As written, they all are linear functions.
If we assume that x3 is supposed to be interpreted as x³ = x^3, and that x2 is supposed to be x² = x^2, then the equations containing those terms are not linear equations.
The equation y = 1/5x is usually interpreted to mean y = (1/5)x. If it is intended to be y = 1/(5x), then it is not a linear function either.
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A linear function is a sum of terms that are either constant or containing a single variable to the first power.
