Y=20x -1500, y equals the prophet, x is the number of books, 20 is the money made after taking out the cost of production, 1500 is a cost that only occurs once.
The answer would be 25 because the square root of 25 is 5.
Answer:
y = (-1/19)(x - 8)² + 1521/76
Step-by-step explanation:
A parabola moves in such a way that it's distance from it's focus and directrix are always equal.
Now, we are given that directrix is y = 9.75 and focus is at (8, 0.25). Focus can be rewritten as (8, ¼) and directrix can be rewritten as y = 39/4
If we consider a point with the coordinates (x, y), it means the distance from this point to the focus is;
√((x - 8)² + (y - ¼)²)
Distance from that point to the directrix is; (y - 39/4)
Thus;
√((x - 8)² + (y - ¼)²) = (y - 39/4)
Taking the square of both sides gives;
((x - 8)² + (y - ¼)²) = (y - 39/4)²
(x - 8)² + y² - ½y + 1/16 = y² - (39/2)y + (39/4)²
Simplifying this gives;
(x - 8)² - (39/4)² = (½ - 39/2)y
(x - 8)² - 1521/4 = -19y
(x - 8)² - 1521/4 = -19y
Divide both sides by -19 to get;
y = (-1/19)(x - 8)² + 1521/76
In a piggy bank, 40% of the coins are dimes.
3/8 of the remainder are nickels.
The remainder is going to be 60%
1/8 of 60% is 7.5%. (just dividing by 8)
3/8 of 60% = 7.5% × 3 = 22.5% are nickels.
If 22.5% are nickels, then 77.5% are not.
The percentage of coins that aren't nickels is the same as the probability of drawing one because each coin has equal probability to be chosen.
