Answer :
A generic line function is based on this format:
[tex]y\text{ = ax + b}[/tex]In this case, 2x + y = 5 we have to isolate 'y' to fill the format above:
[tex]y\text{ = -2x + 5}[/tex]a = -2 and b = 5. So that is a linear function. I will show to you other examples that are not linear:
[tex]y=x^2+2x-4^{}[/tex][tex]y\text{ = }\log _{10}(x)[/tex][tex]y=\sqrt[]{x}[/tex]These are not linear functions because they are not in the y = mx + b format! m and b can be any real number. If m is equal to zero, the function will be constant! Otherwise, if b is equal to zero, the function will be linear.