Question 45078
x          y
-4        -6
0          6
2          12
6          24

How can you tell if this is a linear function and Why?  How do you find the equation for this data.

Notice that as x increases of 0 to 2 y increases by 6 
and when x increases from 2 to 6 y increases by 2(6)=12

This consistent change if y corresponding to a measured increase
in x means the function is linear.

You have two points: (0,6) and (2,12)
Use them to determine the slope = (12-6)/(2-0)=6
Sustitute one of these points and the slope into y=mx+b
to get 6=6(0)+b which implies tht b=6

The eqution is y=6x+6
Cheers,
Stan H.