Question 17
Matrices and DeterminantsSolve for x and y
( 1 1 )( x ) = ( 4 )
( 3 y )( 1 ) ( 1 )
- A.x = −3, y = 8
- B.x = 8, y = 3
- C.x = 3, y = −8
- D.x = 8, y = −3
Show the answer and explanation
Answer: C (x = 3, y = −8)
Explanation
The top row gives x + 1 = 4, so x = 3. The bottom row gives 3x + y = 1, so y = 1 − 9 = −8.