Answer:
<u>The equations system is:</u>
<u>x + y = 10</u>
<u>0.5x + 0.9y = 6</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Liters of 60% acid solution needed = 10
x = Number of liters of the 50% solution
y = Number of liters of the 90% solution
2. Which equation represents the total liters of acid that are needed?
There are two equations needed:
The first one related to the total liters needed, 10 in this case:
x + y = 10
The second one related to the acid concentration of the 10 liters:
0.5x + 0.9y = 10 * 0.6
0.5x + 0.9y = 6
<u>The equations system is:</u>
<u>x + y = 10</u>
<u>0.5x + 0.9y = 6</u>
Solving for x and y in the 2nd equation, we have:
0.5 (10 - y) + 0.9y = 6
5 - 0.5y + 0.9y = 6
0.4y = 6 - 5
0.4y = 1
y = 1/0.4 = 2.5 ⇒ x = 7.5 (10 - 2.5)
The scientist can mix 7.5 liters of the 50% acid solution and 2.5 liters of the 90% acid solution to get the 10 liters of the 60% acid solution.
Answer:
Step-by-step explanation:
5(3)+1=
15+1
16
2(2)^2=
2(4)
8
16 over 8 = 2
Answer:
68 degrees
Step-by-step explanation:
Since the angle is a right angle, it is 90 degrees, to figure out the measurement of a section if it, simply subtract the known angle 22, from 90 to get an answer of 68.
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

and so you would need to add 15 L of pure water to get the desired concentration of acid.
The answer would be 4 1/4 (4.25)
10-1.5=8.5/2=4.25
Hope this helps!
Can u plz mark me as brainliest? I really need it!