Last one:
In the picture a=2, b=4a, b=4•2=8
1st picture a=3, b=4a, b=4•3=12
2nd picture a=0.5, b=4•0.5=2
3rd picture a=2.5, b=4•2.5=10
4th picture a=4, b=4•4=16, but in the picture b=10 therefore, this rectangular is NOT similar to rectangular ABCD.
I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
The question is:
The area of a circular sunspot is growing at a rate of 600 km ^ 2 / sec.
b. How fast is the radius growing at the instant when the sunspot has a area of 640,000 km ^ 2? (Round your answer to 4 decimal places).
For this case the first thing we should know is that by definition the area of the circle is given by:
A = pi * R ^ 2
Where,
R: radio
We must first determine the radius:
R = (A / π) ^ 0.5
R = (640000 / π) ^ 0.5 km
Then, we derive the equation:
A '= pi * (2RR')
We cleared R '
R '= (A') / (2 * π * R)
Substituting values:
R '= (600) / (2π (640000 / π) ^ 0.5)
R '= 0.2116 km / sec
Answer:
the radius is growing at:
R '= 0.2116 km / sec
Answer:
6 mg of the metal needs to be added.
Step-by-step explanation:
Let the amount (in mg) of metal that needs to be added by y.
Therefore, the amount of silver in the above metal is 0.04y.
Prior to mixing, 11 mg of a metal contained 38% of silver (Given).
Therefore, the amount of silver before= 
= 4.18 mg
The total amount of silver after mixing, 4.18 + 0.04y mg
The total amount of metal after mixing, 11 + y mg
New percentage of silver = 26% .
Thus, 
y=6 mg
Therefore, the amount of metal that needs to be added is 6 mg.
If you go to a site called Desmos and type in all these choices you would get your answer a lot faster. But anyways, It would be C.
Hope this helps! :)
