b) 3a + 5b = 3
Step-by-step explanation:
An equation is linear if each term is a constant or is of degree 1, that is, it has only one variable to the first power.
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a) the term containing xy is 2nd-degree
b) all non-constant terms are 1st-degree -- this is a linear equation
c) m^2 is a 2nd-degree term
d) x^2 and y^2 are both 2nd-degree terms