(y_final-y_start)/(x_final-x_start) always! :) that easy
(-6-2)/(2-0) = -4
You probably know that if the interval was pretty small, between 0 and 0.0001, it would take you to the concept of slope and derivatives, but average change is just ignoring anything in between x=0, and x=2 (it could go up/down million times, and still the answer would be -4)
hope it helps
Xy - x - y + 1
explanation: distribute (x-1)(y-1) —> x(y-1) - 1 (y-1) —> xy - x - 1(y-1) —> xy - x - y + 1
Answer:
10+ (4 23 + 7) - 19
I don't know if the 4 is supposed to be multiple or subtract or to add but If it is add
NO they are not proportional
3/7 = .4285714
6/9 = .66666