Answer:
60.96 cm
Step-by-step explanation:
you do proportions
1 in = 2.54
24in= ?
you multiply 2.54 by 24
From the setup of the problem, the "length of the top of the bookcase, measured along the attic ceiling" will be the hypotenuse of a right triangle, the length "AB". We have both the angle between AB and AC and the length of AC (3.24 meters), so we can use trigonometric identities.
The cosine of the 40 degree angle between AB and AC is equivalent to the length of AC divided by the length of AB. Equivalently, we have:

where "h", the hypotenuse, is the length we want. Rearranging the formula to solve for h we have that

which is 4.2295... meters. Converting to centimeters (multiplying by 100) we have that h = 422.95... centimeters, or if we round the value, h = 423 centimeters.
<h3>The worth after 4 years is $ 680.24</h3>
<em><u>Solution:</u></em>
<em><u>The formula for compound interest, including principal sum, is:</u></em>

Where,
A = the future value of the investment
P = the principal investment amount
r = the annual interest rate (decimal)
n = the number of times that interest is compounded per unit t
t = the time the money is invested
From given,
n = 1 ( since interest is compounded annually)
p = 500
t = 4

<em><u>Substituting the values we get,</u></em>

Thus the worth after 4 years is $ 680.24
Answer: -7y+8x
Step-by-step explanation: I assume you mean to simplify
Step 1: Remove parentheses : -4y - x - (3y - 9x)
Step 2: -(3y - 9x) = -3y + 9x
Step 3: Simplify: -4y - x - 3y +9x
Step 4: Answer: -7y+8x