Respuesta :

that is (f(-2)-f(1))/(-2-1)

ust find the slope between the points (-2,f(-2)) and (1,f(1))

f(-2)=(-2)^2+5(-2)-12=4-10-12=-18
f(1)=1^2+5(1)-12=1+5-12=-6

slope between them is (-18-(-6))/(-2-1)=(-18+6)/(-3)=-12/-3=12/3=4
average rate of change is 4
The change in y is -12
The change in x is -3