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
Answer:
g
Step-by-step explanation:
B - 3A = 2
3B - 6A = 12
(2)B - (6)A =4
3B - 6A = 12
Subtract
-B = -8
B = 8
Plugin 8 for B
8 - 3A = 2
8 = 3A + 2
6 = 3A
2 = A
(Double checking)
3(8) - 6A = 12
-6A = 12-24 = -12
- 6A = -12
Divide by -6
A= 2
It works
A = 2. B = 8. Hope this helps
Answer:
<u>86°F</u>
Step-by-step explanation:
Answer:
(x−4)2(x2+4x+16)
Step-by-step explanation:
here hope this helpsss
