Answer:
Step-by-step explanation:
given is a system of linear equations in 3 variables as

This can be represented in matrix form as
AX=B Or
![\left[\begin{array}{ccc}-1&-4&2\\1&2&-1\\1&1&-1\end{array}\right] *\left[\begin{array}{ccc}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}-10\\11\\14\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%26-4%262%5C%5C1%262%26-1%5C%5C1%261%26-1%5Cend%7Barray%7D%5Cright%5D%20%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-10%5C%5C11%5C%5C14%5Cend%7Barray%7D%5Cright%5D)
So solution set
X would be 
|A|=-1(-1)+4(0)+2(-1)=--1
Cofactors of A are
-1 0 -1
-2 -1 -3
0 1 2
So inverse of A is
1 2 0
0 1 -1
1 3 -2
Solution set would be
x=12
y=-3
z=-5
13/ 52 = 1/4 chances.
There are 13 spades and 52 cards. You divide the spades and cards in the deck to find your chances of drawing one.
You have a 25% chance of getting a spade.
Now you put it back. Since you put it back, you still have the same number of cards and the same number of spades. So when you divide 13/52 again, the numbers are still the same. 1/4. 25% chance.
So, you still have a 25% chance the second time around.
Answer:
9
Step-by-step explanation:
Answer:
21
Step-by-step explanation:
PEMDAS