Answer: Choice B)
2x+5(2x+3) = 3
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Reasoning:
We start with the second equation 2x+5y = 3
Since y = 2x+3 from the first equation, we can replace every copy of y with (2x+3). This replacement is valid because y and 2x+3 are the same.
So that's how we go from 2x+5y = 3 to 2x+5(2x+3) = 3
This replacement is done to get rid of the y variable, and it allows us to solve for x later on.
I think The answer is 5100
Answer: 
Step-by-step explanation:
You want to isolate s which means get it by itself. So all you gotta do is divide both sides by t
If the number of downloads of the standard version is x, and the high quality is x, 2.1*x+4.1*y=2761 (not 1010 due to that this is multiplied by 2.1 and 4.1, therefore representing the total amount of megabytes) In addition, there are 1010 total downloads, and it's either 2.1 MB or 4.1 MB, so x+y=1010.
We have
2.1x+4.1y=2761
x+y=1010
Multiplying the second equation by -2.1 and adding it to the first equation, we get 2y=2761-1010*2.1=640 and by dividing both sides by 2 we get y=320 downloads of the high quality version
Answer:
Option C - 1/81
Step-by-step explanation:
9^(-2) = 1/(9^2) [ Because a^(-m) = 1/(a^m) ]
so, 1/(9²) = 1/81.
Hope this helps you.