Solving a system of equations we will see that we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
<h3>
How many liters of each solution do we need to use?</h3>
First, we need to define the variables:
- x = liters of the 35% acid used.
- y = liters of the 80% acid used.
We know that we want to produce 60 liters of 65% acid, then we have the system of equations:
x + y = 60
x*0.35 + y*0.80 = 60*0.65
(in the second equation we wrote the percentages in decimal form).
To solve this we need to isolate one of the variables in one equation and then replace it in other one, isolating x we get:
x = 60 - y
Replacing that in the other equation:
(60 - y)*0.35 + y*0.80 = 60*0.65
y*(0.80 - 0.35) = 60*(0.65 - 0.35)
y*0.45 = 60*0.30
y = 60*0.30/0.45 = 40
So we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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120 + 90 = 210 points
350 - 210 = 140 OR
351 - 210 = 141 (if it must be more than 350, you need <em>at least </em>351 points total, or 141 more points, to get a grade B)
Answer:
(-6,4)
Step-by-step explanation:
The equations are:

Solving for x^2 of the 2nd equation and putting that in place of x^2 in the 2nd equation we have:

Now we can solve for y:

So plugging in y = 4 into an equation and solving for x, we have:

So y = 4 corresponds to x = 6 & x = -6
The pairs would be
(6,4) & (-6,4)
<u><em>we see that (-6,4) falls in the 2nd quadrant, thus this is the solution we are looking for.</em></u>