Answer:
Option A is correct (17,11).
Step-by-step explanation:
6x - 9y = 3
3x - 4y =7
it can be represented in matrix form as![\left[\begin{array}{cc}6&-9\\3&4\end{array}\right] \left[\begin{array}{c}x\\y\end{array}\right] = \left[\begin{array}{c}3\\7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D6%26-9%5C%5C3%264%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D3%5C%5C7%5Cend%7Barray%7D%5Cright%5D)
A= ![\left[\begin{array}{cc}6&-9\\3&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D6%26-9%5C%5C3%264%5Cend%7Barray%7D%5Cright%5D%20)
X= ![\left[\begin{array}{c}x\\y\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D)
B= ![\left[\begin{array}{c}3\\7\end{array}\right]](https://tex.z-dn.net/?f=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D3%5C%5C7%5Cend%7Barray%7D%5Cright%5D)
i.e, AX=B
or X= A⁻¹ B
A⁻¹ = 1/|A| * Adj A
determinant of A = |A|= (6*-4) - (-9*3)
= (-24)-(-27)
= (-24) + 27 = 3
so, |A| = 3
Adj A= ![\left[\begin{array}{cc}-4&9\\-3&6\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-4%269%5C%5C-3%266%5Cend%7Barray%7D%5Cright%5D%20)
A⁻¹ = /3
A⁻¹ = ![\left[\begin{array}{cc}-4/3&3\\-1&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-4%2F3%263%5C%5C-1%262%5Cend%7Barray%7D%5Cright%5D%20)
X= A⁻¹ B
X= ![\left[\begin{array}{cc}-4/3&3\\-1&2\end{array}\right] *\left[\begin{array}{c}3\\7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-4%2F3%263%5C%5C-1%262%5Cend%7Barray%7D%5Cright%5D%20%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D3%5C%5C7%5Cend%7Barray%7D%5Cright%5D)
X= ![\left[\begin{array}{c}(-4/3*3) + (3*7)\\(-1*3) + (2*7)\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D%28-4%2F3%2A3%29%20%2B%20%283%2A7%29%5C%5C%28-1%2A3%29%20%2B%20%282%2A7%29%5Cend%7Barray%7D%5Cright%5D)
X= ![\left[\begin{array}{c}-4+21\\-3+14\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D-4%2B21%5C%5C-3%2B14%5Cend%7Barray%7D%5Cright%5D)
X= ![\left[\begin{array}{c}17\\11\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D17%5C%5C11%5Cend%7Barray%7D%5Cright%5D)
x= 17, y= 11
solution set= (17,11).
Answer:
Solve by adding or subtracting like terms. (Ex. 2k + 4k = 6k; 9 + 7 = 16)
- 6k + 7k = 1k = k
(7 - 6 = 1)
12r - 8 - 12 = 12r - 20
(8 + 12 = 20 but sign is negative) 12r will stay the same because there are no terms with a letter r.
n - 10 + 9n - 3 = 9n + n - 10 - 3 = 10n - 10 - 3 = 10n - 13
(n = 1 so 9 + 1 = 10; 10 + 3 = 13 but negative sign)
- 4x - 10x = 14x
(10 + 4 = 14)
- r - 10r = 11r
(r = 1 so 10 + 1 = 11)
I believe its the secound to last one
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Answer:
4
Step-by-step explanation:
(8)+2=4
16=4
16=4•4
16=16
C. I, II, and III
I’m sure it’s the answer not positive though, I’m sorry.
