Answer:
The answer is 4 liters.
Step-by-step explanation:
We want a final 25% solution, which means that the solvent should constitute 25 percent of all the liters of solution.
Let us call
the litres of 40% solution, so when they are added to the 12 litres of 20% solution, the total litres of the new solution are:

of these liters, 25% must be the solvent:

Now for the 40% solution, the liters of the solvent are
, and for the 20% liter solution, the liters of solve are
liters. Thus the total liters
of the solvent are

Therefore


Answer:
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Among us
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<u><em>Answer:</em></u>either y = 4.5
or y = -4.5
<u><em>Explanation:</em></u>To get the solution, we will need to isolate the y on one side of the equation.
<u>This can be done as follows:</u>
4y</span>²<span> = 81
</span>

<span>
y</span>²<span> = 20.25
y = +/- </span>√(20.25)<span>
either y = +</span>√<span>(20.25) = 4.5
or y = -</span>√<span>(20.25) = -4.5
Since there are no restrictions on the value of y, therefore, both answers would be accepted
Hope this helps :)</span>
There are many answers for a ratio question, and I do not know the choices but since each number could be divided by 30 I would. Do that to get 1:2:3. Hope this helps.