Answer:
f(x) = -4x + 21
Step-by-step explanation:
use the points to find the slope:
[tex](y_2-y_1)/(x_2-x_1)\\\\=(13-5)/(2-4)\\\\=8/(-2)[/tex]
slope is -4
y = -4x + b
plug in one of the available points to find b, let's use (4, 5):
5 = -4(4) +b
5 = -16 + b
b = 21
