Question

HELP PLEASE.....................

Answer 1

Answer:

f(8) = 21

Step-by-step explanation:

First, identify the equation of the line using the form: f(x) =mx + c, where m is the gradient and c is the y-intercept (the constant)

To find gradient, use the rise over run formula: (y2 - y1)/(x2 - x1)

You can use any points but I am going to use (2,3) and (3,6)

(6 - 3)/(3 - 2)

3/1 = 3      (gradient of the graph is 3)

Hence the equation is simplified to: f(x) = 3x + c

Now we need to find the value for c. To do this, you sub in any point, and I am going to use (3,6)

6 = 3*(3) + c   (rearrange it to make c on its own)

6 - 9 = c

c = -3

Hence the equation of the line is: f(x) = 3x - 3

So we are trying to figure out what f(8) equals. That means we sub in the value 8 where x is.

3*(8) - 3 = 21

f(8) = 21