Answer:
X=5
Step-by-step explanation:
2X+7=5X-8
7=3X-8
15=3X
5=X
Answer: A. 
B. A'(5) = 1.76 cm/s
Step-by-step explanation: <u>Rate</u> <u>of</u> <u>change</u> measures the slope of a curve at a certain instant, therefore, rate is the derivative.
A. Area of a circle is given by

So to find the rate of the area:


Using 

Then
![\frac{dA}{dt}=2.\pi.r.[\frac{726}{(t+11)^{3}}]](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%3D2.%5Cpi.r.%5B%5Cfrac%7B726%7D%7B%28t%2B11%29%5E%7B3%7D%7D%5D)
![\frac{dA}{dt}=2.\pi.[3-\frac{363}{(t+11)^{2}}].\frac{726}{(t+11)^{3}}](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%3D2.%5Cpi.%5B3-%5Cfrac%7B363%7D%7B%28t%2B11%29%5E%7B2%7D%7D%5D.%5Cfrac%7B726%7D%7B%28t%2B11%29%5E%7B3%7D%7D)
Multipying and simplifying:

The rate at which the area is increasing is given by expression
.
B. At t = 5, rate is:




At 5 seconds, the area is expanded at a rate of 1.76 cm/s.
A is inbetween 2 and 4
B is inbetween 3 and 4
C is inbetween 4 and 5
D is inbetween 5 and 6
So the correct answer would be A B and C
1.
5514 divided by 82 you have to find out how many times 82 goes into 551 (because it won't go into 5 or 55 now 82 goes into 551 6 times and you multiply 82 and 6 to get 492 (which is the closest you can get to 551 without going over) now you subtract 551-492 to get 59 now you carry down your 4 and add it to the end of the equation and your number changes into 594 now 82 times 7 is 574 when you subtract you get 20 now you add a decimal point and you carry down the 0 to make your number 200 now you do 82 times 2 to get 164 when you subtract you get 36 now you carry down the 0 and get 360 so you multiply 82 by 4 to get 328 so your answer is 67.24.Hope this helps. I can add a picture if you need one.