Answer:

Step-by-step explanation:
To find the average rate of change of a function over a given interval, basically you need to find the slope. The mathematical definition of the slope is very similar to the one we use every day. In mathematics, the slope is the relationship between the vertical and horizontal changes between two points on a surface or a line. In this sense, the slope can be found using the following expression:

So, the average rate of change of:

Over the interval 
Is:


Therefore, the average rate of change of this function over that interval is 3.
Answer:
it 1/3
Step-by-step explanation:
2/4 is just 1/2, 3/6 is also 1/2, 7/9 is over 1/2 and 1/3 is the only one less then 1/2 so it's the lowest fraction. This is not the proper way to solve it but it works and it's faster
Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present
Answer:
17.5 hours
Step-by-step explanation:
107 = 60(2^n)
n(lg2) = lg(107/60)
n = 0.8345763908 × 21
n = 17.52610421 hours