Answer:
-136
Step-by-step explanation:
We have to find the determinant of the following matrix:
![\left[\begin{array}{ccc}-4&5&6\\0&4&4\\-2&-5&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-4%265%266%5C%5C0%264%264%5C%5C-2%26-5%264%5Cend%7Barray%7D%5Cright%5D)
We can find the determinant by expanding via 1st column. i.e. by taking each element of 1st column and multiplying it by its co-factor matrix as shown below:
det
= ![(-4 \times det \left[\begin{array}{cc}4&4\\-5&4\end{array}\right]) - (0 \times (-4 \times det \left[\begin{array}{cc}5&6\\-5&4\end{array}\right]))+ ((-2) \times det\left[\begin{array}{cc}5&6\\4&4\end{array}\right])\\\\ =-4 \times (16 + 20)-(0)+(-2 \times 20-24)\\\\ =-4(36)+(-2(-4))\\\\ =-144+8\\\\ =-136](https://tex.z-dn.net/?f=%28-4%20%5Ctimes%20det%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D4%264%5C%5C-5%264%5Cend%7Barray%7D%5Cright%5D%29%20-%20%280%20%5Ctimes%20%28-4%20%5Ctimes%20det%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%266%5C%5C-5%264%5Cend%7Barray%7D%5Cright%5D%29%29%2B%20%28%28-2%29%20%5Ctimes%20det%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%266%5C%5C4%264%5Cend%7Barray%7D%5Cright%5D%29%5C%5C%5C%5C%20%3D-4%20%5Ctimes%20%2816%20%2B%2020%29-%280%29%2B%28-2%20%5Ctimes%2020-24%29%5C%5C%5C%5C%20%3D-4%2836%29%2B%28-2%28-4%29%29%5C%5C%5C%5C%20%3D-144%2B8%5C%5C%5C%5C%20%3D-136)
The notation det() stands for determinant of the matrix.
Therefore, the determinant of the given matrix is -136
Answer:
48
Step-by-step explanation:
3 times 13 (john's age) = 39
39 + 9 = 48 (nine years older than 3 times (39) so you add 9)
Therefore, Tim is 48.
Answer:
B. -2.3
Step-by-step explanation:
It looks like the graph goes down about 7, and over 3, so B makes sense.
Answer:
total population: 9,000
10% of 9,000= 900 students
they only surveyed 800 students so Yes the 10(800)=8,000 which is less then 9,000 or Option A
Take the complex zero 1+i. There must be another zero 1-i to balance it, so we have the factors (x-1-i)(x-1+i)=x²-2x+1+1=x²-2x+2.
So the polynomial is (x+3)(x²-2x+2)=x³-2x²+2x+3x²-6x+6=x³+x²-4x+6, option D.
