Answer:
-7
Step-by-step explanation:
To find f(-8), use the blue line labeled f(x) and go to -8 on the x axis and find its corresponding y value by moving vertically down from -8 to the blue line and find the y value of that point. You can see that the blue line hits (-8, -5) so the y value is -5 and f(-8) = -5.
Do the same thing for g(4) and you should find the red graph g(x) hits the point (4, 3). So g(4) = 3.
-1 * -5 - 4 * 3 = 5 - 12 = -7