Discover answers to your questions with Westonci.ca, the leading Q&A platform that connects you with knowledgeable experts. Discover in-depth answers to your questions from a wide network of experts on our user-friendly Q&A platform. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.
Sagot :
Answer is b. (-1, -5)
Step by step
Substitute the x and y values into both equations to find equality
Answer b. Makes both equations equal
2x + y = -7
2(-1) + (-5) = -7
-2 -5 = -7
-7 = -7
It equals now let’s do the 2nd one
x - y = 4
-1 -(-5) = 4
4 = 4
This one equals too. I did the math on the other three answers and they did not equal.
Problem solved!
Step by step
Substitute the x and y values into both equations to find equality
Answer b. Makes both equations equal
2x + y = -7
2(-1) + (-5) = -7
-2 -5 = -7
-7 = -7
It equals now let’s do the 2nd one
x - y = 4
-1 -(-5) = 4
4 = 4
This one equals too. I did the math on the other three answers and they did not equal.
Problem solved!
Answer: B. (-1, -5)
Step-by-step explanation:
Given equations
2x + y = -7
x - y = 4
Concept
[tex]A^{-1}=\frac{1}{ad-bc}\left[\begin{array}{ccc}a&b\\c&d\\\end{array}\right][/tex]
[tex]A*A^{-1}=A^{-1}*A=I~(Which~is~basically~1)[/tex]
Convert into matrix
[tex]\left[\begin{array}{ccc}2&1\\1&-1\\\end{array}\right] \left[\begin{array}{ccc}x\\y\\\end{array}\right]=\left[\begin{array}{ccc}-7\\4\\\end{array}\right][/tex]
Calculate the inverse of the matrix
[tex]A=\left[\begin{array}{ccc}2&1\\1&-1\\\end{array}\right][/tex]
[tex]A^{-1}=\frac{1}{ad-bc}\left[\begin{array}{ccc}a&b\\c&d\\\end{array}\right][/tex]
[tex]A^{-1}=-\frac{1}{3} \left[\begin{array}{ccc}-1&-1\\-1&2\\\end{array}\right][/tex]
Solve by multiplying the inverse of the matrix
[tex]A*A^{-1}=A^{-1}*A=I[/tex]
[tex]-\frac{1}{3} \left[\begin{array}{ccc}-1&-1\\-1&2\\\end{array}\right]\left[\begin{array}{ccc}2&1\\1&-1\\\end{array}\right] \left[\begin{array}{ccc}x\\y\\\end{array}\right]=-\frac{1}{3} \left[\begin{array}{ccc}-1&-1\\-1&2\\\end{array}\right]\left[\begin{array}{ccc}-7\\4\\\end{array}\right][/tex]
[tex]1*\left[\begin{array}{ccc}x\\y\\\end{array}\right]=-\frac{1}{3}\left[\begin{array}{ccc}3\\15\\\end{array}\right][/tex]
Simplify by multiplication
[tex]\left[\begin{array}{ccc}x\\y\\\end{array}\right]=\left[\begin{array}{ccc}-1\\-5\\\end{array}\right][/tex]
Therefore, the answer is [tex]\Large\boxed{(-1,~-5)}[/tex]
Hope this helps!! :)
Please let me know if you have any questions
We hope you found this helpful. Feel free to come back anytime for more accurate answers and updated information. Thanks for stopping by. We strive to provide the best answers for all your questions. See you again soon. We're glad you visited Westonci.ca. Return anytime for updated answers from our knowledgeable team.
