Answer:
3 * 10^6 if the answer is 3.64 * 10^6, you really ought to argue the meaning of estimate with your instructor.
Step-by-step explanation:
This is a very valuable question. Put your calculator away when you answer it. Using a calculator is sort of cheating.
1.3 * 10^3 roughly is roughly 1 * 10^3
2.8*10^3 hours is roughly 3 * 10^3
Forget the powers for now and just work with the 1 and 3
1*3 equals 3.
10^3 * 10^3 = 10^6 when the base of two numbers is the same (10 in this case) then the powers are added.
10^(3 + 3) = 10^6
So the answer is roughly 3*10^6
Now you can take out your calculator and get the answer.
1.3*10^3 * 2.8 * 10^3 = 3.64 * 10 ^ 6
Notice that the estimate (done in my head) is close enough to tell you what the answer should be. On a test, that's a very handy skill.
66 cents each I have to add more characters so ignore this part
Answer:
Step-by-step explanation:
S=4πr²
ds/dt=4π×2r×dr/dt=8πr dr/dt
dr/dt=60 cm/min
ds/dt=8π×60r=480πr
r=16,t=0
at t=2,r=16+32=48 cm
so ds/dt=480π×48=23040 πcm²≈72382.79 cm²
2.

The angle BCD = 120°
<h3>Further explanation</h3>
Given
A parallelogram and four angles
Required
Angle BCD
Solution
In A parallelogram
The sum of the four angles is 360°
Opposite angles are equal
/congruent(A=C, B=D)
Consecutive angles are supplementary (A + D = 180 °, D + C = 180°, C + B = 180°, B + A = 180°).
We choose a solution by using
Consecutive angles :
∠C+∠B=180°
18x=180°
x=10
∠C=∠BCD =

Or we can use another ways :
The sum of the four angles is 360°
∠A+∠B+∠C+∠D=360°
12x+6x+12x+6x=360°
36x=360°
x=10
∠C=∠BCD =

I think it's A because of PEMDAS so you multiply 8 by n-3