-5-12=-17 so it is b)
Answer:
I believe it's A and B
Step-by-step explanation:
y = 1
x = -1
x - 2y = -3, then x = 2y - 3
2x + y = -1
substitute for x:
2(2y - 3) + y = -1
4y - 6 + y = -1
5y = 5
x = 2 - 3 = -1
on the matrix gives![\left[\begin{array}{cc|c}5&5&5\\1&-\dfrac23&5\end{array}\right]\to\left[\begin{array}{cc|c}1&-\dfrac23&5\\5&5&5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D5%265%265%5C%5C1%26-%5Cdfrac23%265%5Cend%7Barray%7D%5Cright%5D%5Cto%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Cc%7D1%26-%5Cdfrac23%265%5C%5C5%265%265%5Cend%7Barray%7D%5Cright%5D)