Answer:
60 pages
Step-by-step explanation:
Day 1 : 1/3 book
Day 2: 1/4 book
Day 3: 1/5 book
Day 4: 13 pages
Total days 1 through 3 = 1/3 + 1/4 + 1/5 = 20/60 + 15/60 + 12/60 = 47/60
Day 4 = 1 - 47/60 = 13/60
Pick 2 pairs of equations t<span>hen use addition and subtraction to eliminate </span>the same variable<span> from both pairs of equations then it is left with 2 variables
</span>Pick two pairs
<span><span>4x - 3y + z = - 10</span><span>2x + y + 3z = 0
</span></span>eliminate the same variable from each system
<span><span>4x - 3y + z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>4x - 3y + z = - 10</span>
<span>-4x - 2y - 6z = 0</span>
<span>-5y - 5z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>- x + 2y - 5z = 17</span>
<span>2x + y + 3z = 0</span>
<span>-2x + 4y - 10z = 34</span>
<span>5y - 7z = 34
</span></span>Solve the system of the two new equations:
<span><span>-5y - 5z = - 10</span>
<span>5y - 7z = 34</span>
<span>-12z = 24</span>
which is , <span>z = - 2</span>
<span>-5y - 5(- 2) = - 10</span>
<span>-5y = - 20</span>
wich is , <span>y = 4
</span></span>substitute into one of the original equations
<span>- x + 2y - 5z = 17</span>
<span>- x + 2(4) - 5(- 2) = 17</span>
<span>- x + 18 = 17</span>
<span>- x = - 1</span>
<span>x = 1</span>
<span>which is , </span><span>(x, y, z) = (1, 4, - 2)</span><span>
</span>Does 2(1) + 4 + 3(- 2) = 0<span> ? Yes</span><span>
</span>
What's the question or what you are trying to find
each term is negative and 1/4 of previous term so the nth term is the n-1 term times -1/4 so f(n)= -1/4 f(n-1)
The derivatives for this problem are given as follows:
a) 
b)
.
<h3>What is the derivative of the sum?</h3>
The derivative of the <u>sum is the sum of the derivatives</u>.
In this problem, the function is:

Using a derivative table for the derivatives of the cosine and the ln, the derivative of the function is:


What is the product rule?
The derivative of the product is given as follows:

In this problem, we have that:
.
.
Hence the derivative is:
.
More can be learned about derivatives at brainly.com/question/2256078
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