We want to see how much pure water and 80% salt solution should be mixed to get 20 ounces of a 50% salt solution, we will solve this by using a system of equations. We will see that we need to use <u>7.5 ounces of pure water</u> and <u>12.5 ounces of the 80% salt solution.</u>
<h3>
How to get the system of equations?</h3>
We should start by defining the variables we will be using, these are:
- x = ounces of pure water used
- y = ounces of the 80% solution used.
We know that we want to end with 20 ounces of the mixture, then we have:
x + y = 20
We also know that the percentage of salt in the final mixture must be 50%, which means that a 0.5 of the final mixture is salt, then we have:
0*x + 0.8*y = 0.5*20
(the first 0 is because we have no salt in the pure water, and the 0.8 is because we have 80% of salt in the 80% mixture)
So we got the two equations needed, thus the system of equations is:
x + y = 20
0*x + 0.8*y = 0.5*20
With the second one we can get the value of y:
0*x + 0.8*y = 0.5*20
0.8*y = 0.5*20 = 10
y = 10/0.8 = 12.5
This means that we must use 12.5 ounces of the 80% solution, and we need to use:
x = 20 - y = 20 - 12.5 = 7.5
7.5 ounces of pure water.
If you want to learn more about systems of equations, you can read:
brainly.com/question/13729904
well, we know is a line, and to get the equation of any straight line all we need is two points, hmmm let's use from the table hmm say (2 , -50) and hmmm (4 , -88)
Answer:
72
Step-by-step explanation:
18*4
12*6
8*9
Answer:
C. x + 2y = 10
-4x - y = 2
Step-by-step explanation:
A. quickest way is to plug in -2, 6 and see which one works
B. this is the other way
1. x + 2y = 10
-4x - y = 2
2. multiply 4 with x + 2y = 10 so i can get 4x + 8y = 40
i want +4x so i can cancel with the -4x in -4x - y = 2
3.
4x + 8y = 40
-4x - y = 2
--------------------
7y = 42
y = 6
4. then plug in 6 into an equation to get x
-4x - y = 2
-4x -6 = 2
-4x = 8
x = -2
