To convert any unit to it's "milli-" form always multiply the given value by 1000. The new value will be the value of in the "milli-" form.
The question asked to us is to convert 3.521 g to mg (or milligram). Thus, all that we need to do is to multiply 3.521 with 1000 and we will get the corresponding value in milligrams. Thus, in mg, 3.521 g is:
mg
Given:
The ratio of red and blue cubes is 4:7.
After adding 10 more red cubes the ratio of red and blue cubes is 6:7.
To find:
The number of blue cubes.
Solution:
The ratio of red and blue cubes is 4:7.
Let the number of red and blue cubes be 4x and 7x respectively.
After adding 10 more red cubes.
Number of red cubes = 4x+10
Then, the ratio of red and blue cubes is 6:7.





Divide both sides by 14.

Now,
Number of blue cubes in the bag is

Therefore, the number of blue cubes is 35.
Answer: 
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Work Shown:
Apply the following trig identity

Now let's rationalize the denominator

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As confirmation, you can use the idea that if x = y, then x-y = 0. We'll have x = tan(165) and y = -2+sqrt(3). When computing x-y, your calculator should get fairly close to 0, if not get 0 itself.
Or you can note how

which helps us see that they are the same thing.
Further confirmation comes from WolframAlpha (see attached image). They decided to write the answer as
but it's the same as above.
A. -2x + 3y = -15
-2x + 2x + 3y = 2x - 15
3y = 2x - 15
3 3
y = ²/₃ - 5
A is correct.
B. y = ²/₃ - 5
B is also correct.
C. 6y = 4x - 30
6 6
y = ²/₃x - 5
C is also correct.
D. y + 3 = ²/₃(x - 3)
y + 3 = ²/₃(x) - ²/₃(3)
y + 3 = ²/₃x - 2
- 3 - 3
y = ²/₃x - 5
D is also correct.
The answer to the problem is A, B, C, and D.
45 times .3 =13.5 okkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk