Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have
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and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
See attachment
Step-by-step explanation:
First solve this like a normal equation:
-3x - 6 > 9
Add 6 to both sides:
-3x > 9 + 6
-3x > 15
Divide by -3 and remember to switch the inequality sign:
x < 15/(-3)
x < -5
Think about the graph of x = -5. It's a vertical line crossing the y-axis at x = -5. Now, we have x is less than -5. That means all the values less than -5 should be viable solutions. So, shade the part of the graph to the left of the vertical line.
Also, since we have x < -5 and not x ≤ -5, the line should be dotted.
See graph attached.
<em>~ an aesthetics lover</em>
Answer:
x = 8, y = 3
Step-by-step explanation:
Equating corresponding x and y coordinates , then
- y = - x + 5 ( multiply through by - 1 )
y = x - 5 → (1)
2x - 5y = 1 → (2)
Substitute y = x - 5 into (2)
2x - 5(x - 5) = 1 ← distribute and simplify left side
2x - 5x + 25 = 1
- 3x + 25 = 1 ( subtract 25 from both sides )
- 3x = - 24 ( divide both sides by - 3 )
x = 8
Substitute x = 8 into (1) for corresponding value of y
y = 8 - 5 = 3
This answer uses NMF, which you can find out about on my profile:
Preliminary work:
Following the BIDMAS order of operations, we can calculate part of it already, and that's the 2•4, which equals 8.
Therefore, the equation now reads:
8+x = y
x = 5:
8+5 = 13
13 ≠ 16
13 ≠ y
x = 4:
8+4 = 12
12 = 12
12 = y
Therefore, the pair is (4, 12)