How can you tell if an equation of a relation represents a linear relation?

Answer 1

THanks to everyon who helps :)

Answer 2

linear = first degree only, no squares, no cubes, no square roots,no products of variable.

so x+3y=c is a linear equation
x^3+y=c is NOT
-x+12y=45 is linear
1+ xy=c is NOT

Answer 3

thanks so much that helped me a lot !!