Answer:
C, f(x) = 2x + 6
Step-by-step explanation:
First, we need to plug in the values of the x coordinates and see if it matches with the y coordinate to determine if it is on the same line. Startin with 2x + 8, we have the point (1, 8) on the graph. Plugging in 1 gets you 10 for the y. This is wrong since 8 is the y coordinate. Moving on, we have 6.4(1.25)^x for the same point. Plugging in 1, we have 6.4 * 1.25 = 8, which is true. Moving on to the second point, (2, 10), we have 1.25 squared times 6.4. This is thus wrong. So, moving on to 2x + 6, we have the point (1, 8), and plugging in 1 for x, we have 8 as y. Since this satisfies the equation we move on to the next point, (2,10). Plugging in x, we have 2 * 2 + 6 = 10, which is also true. Moving on to our third point (3 , 12), we plug in 3 for x. We then get 3 * 2 + 6 = 12, which is correct. This, is our answer then.