Orlando S. answered 01/19/23
Middle/High School Mathematics and Physics Tutor
Hi, Kellyn!
The key to this problem is to note that a coefficient matrix is formed by inputting the coefficients of each of the variables in the system of equations.
Let's label 5x - y = 6 as Equation A. In this equation, both x and y have a coefficient, which we will label Ax and Ay. The values of these coefficients are Ax = 5 and Ay = -1.
We can analyze 2x + 7y = 9 (Equation B) in the same way, which would give us Bx = 2 and By = 7.
We can then assemble our coefficient matrix, which takes the form of a 2x2 matrix with the A coefficients in the top row and the B coefficients in the bottom row.
( Ax Ay
Bx By ) (the parentheses should be large and encompass all of the values)
We can then plug in our values to obtain the following matrix:
( 5 -1
2 7 )
I hope that this explanation is helpful, and please don't hesitate to reach out if you have any further questions!