Answer:
The constant 2.2 in L(D) represent the brightness in lumens per square inch.
Step-by-step explanation:

Answer: All real numbers except 3
Hello! In order to find a linear function without graphing it, we can see if the x-values (domain) has more than one value of y (range) out of this set of ordered pairs. Those ordered pairs represent a linear function, because each x-value does not have more than 1 y-value. Therefore, those points satisfies a function.