Answer:
-21
Step-by-step explanation:
I assume this is a 2 by 2 matrix.

determinant = -5 * 4 - 1 * 1 = -20 - 1 = -21
Answer:
A
C
i don't get the first slide
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
I believe the answer is B because if we multiply the top equation by 6, we get 48x + 30y = -42, and if we multiply the bottom equation by -5, we get
35x - 30y = 20. So now, if we add it all together, then the positive 30y and negative 30y cancel out aka it equals 0, and thus the variable y is gone, satisfying the requirement that the problem asks for ("Which of these strategies would eliminate a variable...").
I hope this helped, and if it's correct, I'd appreciate if you marked my answer as Brainliest :)
AngleGEF, the first option!!
A(3,4) B(-2.7) C(-3,2) D(3,0)
Add 1 to the 1st # of each
Add 2 to the 2nd #of each