Your answer would be:
5.2*10^(-3)
hope this helps!
happy thanksgiving
You have to isolate x. First you start off by adding the like terms which is -3x and -x. By adding them you get -4x.
8 - 4x = 12
Then you subtract 8 on both sides since it is positive to isolate x.
-4x = 4
Then you divide -4 by both sides and get x=4/-4
4/-4 is simplified to -1 so the answer is x= -1
x^5 is your answer because you add exponents when they are not in separate paretheses.
Answer: choice A. 40 liters
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Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
