Question

1. What is the determinant of the matrix?
[5 6]
[2 9]

a. -33
b. 6
c. -6
d. 33 <---- my answer


2. What is the determinant of the matrix?
[-4 -5]
[ 2 -6]

a. -14
b. -34
c. 14
d. 34 <---- my answer


3. Which expression gives the x-coordinate of the solution of the system?
2x+3y=5
3x+5y=7

a.
|2 5|
|3 7|
________
|2 3|
|3 5|

b.
|2 5|
|3 7|
________
|5 3|
|7 5|

c.
|5 2|
|7 3|
________
|2 3|
|3 5|

d.
|5 3|
|7 5|
________
|2 3|
|3 5|

Answer 1

I agree with your first two answers.

Do you have an answer for the 3rd one?

Answer 2

D =
|2 3|
|3 5|
so B is out

Replace the 1st column with (5,7) and that gives D.