Respuesta :
To make 100 ml of 25% saline solution, Riley will need 50 ml = 12% saline mixture and 50 ml= 38% saline mixture.
Given,
We have 12% and 38% of saline mixtures.
We need to find the amount in ml from each saline mixture which would give us 100 ml of 25%.
What are the methods to solve a system of linear equations?
There are a number of methods but the most and easiest used method is the substitution method and the elimination method.
We can make two linear equations from the given statements.
Let x = amount from 12% saline mixture and y = amount from 38% saline mixture.
Now we need to make 100 ml of 25% saline.
so,
x + y = 100.
So we have two equations.
x + y = 100..............(1)
12% of x + 38% of y = 100 x 25%
0.12x + 0.38 = 25 ...............(2)
Using the substitution method we have,
x = 100 - y
Putting x = 100 - y in {2}
0.12 ( 100 - y ) + 0.38y
= 2512 - 0.12y + 0.38y
= 250.38y - 0.12y
= 25 - 120.26y = 13y
= 13 / 0.26y = 50.
Putting y = 50 in (1)
x + y = 100x
100 -50x = 50.
So Riley will need 50 ml = 12% saline mixture and 50ml = 38% saline mixture to make 100 ml of 25% saline solution.
Learn more about finding proportion of mixtures here:
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