What is the value of ?A. 7.5 B. 17.5 C. 60.5 D. 76.5

Mathematics

2 answers:

REY [17]4 years ago

8 0

Answer:

76.5

Step-by-step explanation:

Recall that for any positive integer n

n! = 1*2*3*4*...*n

For example

5! = 1*2*3*4*5 = 120

$\sum_{n=2}^6\frac{(n-1)!}{2}=\frac{(2-1)!}{2}+\frac{(3-1)!}{2}+\frac{(4-1)!}{2}+\frac{(5-1)!}{2}+\frac{(6-1)!}{2}=\\\\=\frac{1!}{2}+\frac{2!}{2}+\frac{3!}{2}+\frac{4!}{2}+\frac{5!}{2}=\frac{1}{2}+\frac{1*2}{2}+\frac{1*2*3}{2}+\frac{1*2*3*4}{2}+\frac{1*2*3*4*5}{2}=\\\\=\frac{1}{2}+1+3+12+60=\boxed{76.5}$

Marina CMI [18]4 years ago

7 0

Answer:

D on edge

Step-by-step explanation:

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Solve for x: −5|x + 1| = 10

11Alexandr11 [23.1K]

Answer:

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Step-by-step explanation:

6 0

3 years ago

What is the product of the two matrices? Fill in the missing elements of the resulting matrix.

olganol [36]

The product of the given two matrices comes out to be $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Here we are given the 2 matrices as follows-

$\left[\begin{array}{ccc}7&-2\\-6&2\end{array}\right] \left[\begin{array}{ccc}1&1\\3&3.5\end{array}\right]$

To find the product of 2 matrices, the number of columns in the first matrix must be equal to the number of rows in the second matrix.

Here since both of the matrices are 2 × 2, their product is possible.

Now, to find the product, we need to multiply each element in the first row by each element of the 1st column of the second matrix and then find their sum. Similarly, we do this for all rows and columns.

Therefore,

$\left[\begin{array}{ccc}(7*1)+(-2*3)&(7*1)+(-2*3.5)\\(-6*1)+(2*3)&(-6*1)+(2*3.5)\end{array}\right]$