the area of the model is 113.75
Answer:
AB = ![\left[\begin{array}{ccc}-3&4&6\\-6&3&5\\5&0&-4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-3%264%266%5C%5C-6%263%265%5C%5C5%260%26-4%5Cend%7Barray%7D%5Cright%5D)
Each column of AB is written as a linear combination of columns of Matrix A in the explanation below.
Step-by-step explanation:
A = ![\left[\begin{array}{ccc}-2&2&1\\-3&1&1\\2&0&-1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%262%261%5C%5C-3%261%261%5C%5C2%260%26-1%5Cend%7Barray%7D%5Cright%5D)
B= ![\left[\begin{array}{ccc}2&-1&0\\1&2&1\\-1&-2&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%26-1%260%5C%5C1%262%261%5C%5C-1%26-2%264%5Cend%7Barray%7D%5Cright%5D)
We need to write each column of AB as a linear combination of the columns of A so we will multiply each column of A with each column element of B to get the column of AB. So,
AB Column 1 = 2 * ![\left[\begin{array}{ccc}-2\\-3\\2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%5C%5C-3%5C%5C2%5Cend%7Barray%7D%5Cright%5D)
+ 1 ![\left[\begin{array}{ccc}2\\1\\0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%5C%5C1%5C%5C0%5Cend%7Barray%7D%5Cright%5D)
+ (-1) ![\left[\begin{array}{ccc}1\\1\\-1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%5C%5C1%5C%5C-1%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}-3\\-6\\5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-3%5C%5C-6%5C%5C5%5Cend%7Barray%7D%5Cright%5D)
AB Column 2 = (-1) + 2 + (-2) = ![\left[\begin{array}{ccc}4\\3\\0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%5C%5C3%5C%5C0%5Cend%7Barray%7D%5Cright%5D)
AB Column 3 = (0) + (1) + 4 = ![\left[\begin{array}{ccc}6\\5\\-4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%5C%5C5%5C%5C-4%5Cend%7Barray%7D%5Cright%5D)
Finally, we can combine all three columns of AB to form the 3x3 matrix AB.
AB =
Answer:
C. 1/(x^2 +1) > 0
Step-by-step explanation:
The cube of a negative number is negative, eliminating choices B and D for certain negative values of x.
1/x^2 is undefined for x=0, so cannot be compared to zero.
The value 1/(x^2+1) is positive everywhere, so that is the expression you're looking for.
1/(x^2 +1) > 0
Answer: So lets say that the width is w. The length(L) is 4 meters greater than 3 times the width. 3 times the width would be 3w, and then 4 meters greater than that would be 3w+4. You have two widths and two lengths to a rectangle that must add up to equal 72. So 2w + 2L =72. But remember that one L equals 3w+4
2(w) + 2(3w+4) = 72
2w+6w+8=72
8w+8=72
8w=64
w=8
L=3w+4
L=3(8)+4
L=24+4
L=28
So the dimensions are 8 meters by 28 meters
To check 2(8)+2(28)=72
87% of 73 is about 63.51 and 73% of 87 is 60.59 so 87% of 73 is greater
