Answer: choice A. 40 liters
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Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
Answer: choice D) 20
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Explanation:
Locate 3 on the x axis number line. Draw a vertical line through 3 and this vertical line will cross the parabola at some point P. Mark this point P on the parabola. Then draw a horizontal line from P to the y axis. The horizontal line will land on y = 10. In short, this all shows us that (3,10) is a point on this parabola.
Repeat those steps above, but now for x = 7. You'll see that (7,90) is another point on this parabola.
We need to find the slope of the line through the two points (3,10) and (7,90). The average rate of change from x = 3 to x = 7 is the same as the slope of the line through those two points.
To find the slope, we use the slope formula
m = (y2 - y1)/(x2 - x1)
where (x1,y1) and (x2,y2) are the two points, and m is the slope
In this case,
(x1,y1) = (3,10) and (x2,y2) = (7,90)
further breaking down to
x1=3
y1=10
x2=7
y2=90
So we'll plug those four pieces of info into the equation and simplifying to get...
m = (y2 - y1)/(x2 - x1)
m = (90 - 10)/(7 - 3)
m = 80/4
m = 20
The slope of the line is 20, so therefore, the average rate of change is 20.
For this case, the arithmetic sequence is given by:
an = 17n-1
Let's check it:
First week:
n = 1:
a1 = 17 (1) -1
a1 = 17-1
a1 = 16
Second week:
n = 2:
a2 = 17 (2) -1
a2 = 34-1
a2 = 33
Third week:
n = 3:
a3 = 17 (3) -1
a3 = 51-1
a3 = 50
Answer:
the explicit rule for the arithmetic sequence that defines the number of boxes of cereal sold in week n is:
an = 17n-1
Answer:
The slope is 
Step-by-step explanation:
The slope of the line passing through 
and 
is given by the formula;
The given line contains;the points (2, -6) and (-3, 1).
The slope is
Answer:
x= 11/12
Step-by-step explanation:
12x - 1 = 10
12x = 10 + 1
12x = 11, divide 11 by 12
you can't divide it evenly so leave it as a fraction.
