Answer:
2
Step-by-step explanation:
Khan acaremy
Answer:
Interval [b,c] and interval [c,d]
Step-by-step explanation:
a(-5,0)
b(-1,2)
c(4,3)
d(11,4)
The average rate of change is the the total rise over the total run.
The Rise means the vertical increase and the Run means horizontal incease.
For interval [a,b]
rate of change is 
For [b,c]

For [c,d]

Is there more to this problem? By saying f(4), you'd be inputting a 4 for every variable x. There is not enough info here to answer the question.
Answer:
14. x=-2.5, y = -7
15. x=28 y = -20
Step-by-step explanation:
14. Let's solve this system by elimination. Multiply the first equation by -1.
-1*(4x-y)= -1*(- 3)
-4x +y = 3
Then add this to the second equation.
-4x+y = 3
6x-y= - 8
--------------
2x = -5
Divide each side by 2
x = -2.5
We still need to find y
-4x+y =3
-4(-2.5) + y =3
10 +y =3
Subtract 10 from each side.
y = 3-10
y = -7
15.I will again use elimination to solve this system, because using substitution will give me fractions which are harder to work with. I will elimiate the y variable. Multiply the first equation by 11
11(
5x+6y)= 11*20
55x+66y = 220
Multiply the second equation by -6
-6(9x+11y)=32*(-6)
-54x-66y = -192
Add the modified equations together.
55x+66y = 220
-54x-66y = -192
---------------------------
x = 28
We still need to solve for y
5x+6y = 20
5*28 + 6y =20
140 + 6y = 20
Subtract 140 from each side
6y = -120
Divide by 6
y = -20
40
8x5=40
10x4=40
Hope this helps