The answer is 67 point 18.
If there are 7 books on the floor, 7 x 3 is 21. Plus two extra books, 21 + 2 = 23. There are 23 books on the bookshelf.
(6x–1)(6x+1) - 4x(9x+2) = −1
Simplify the left side:
36x^2-1 -36x^2-8x = -1
Combine like terms:
-1 -8x = -1
Add 1 to both sides:
-8x = 0
Divide both sides by -8:
x = 0 / -8
x = 0
The root is 0
Analyzing the given values and the given equation, we have the following:
A = $25,000
r = 0.11
t = 6
The equation has the form:
y = A (1-r)^t
Plugging in the given values into the equation,
y = $25,000 (1 - 0.11)^6
y = $25,000 (0.89)^6
Therefore, the answer is
A. y=25,000(.89)^6
Answer: She would have to practice for 3/4 of an hour left to reach her goal