It's suppose to be -18 so I guess no real number....
Answer:
Step-by-step explanation:
I haven't got time to do all these by I'll give you the method in each case.
You have to make the x or y term equal (or 1 term + and other -) in both equations before adding or subtracting.
A . Multiply equation 2 by 2 and subtract (to eliminate x)
- don't forget to multiply EACH TERM by 2.
B. Multiply equation 2 by -2 and add.
C. Multiply equation 1 by 3 and equation 2 by 2 ( this will give -6y and +6y in the resulting equations ) so you then add to eliminate y.
D. Multiply equation 1 by 13 and equation and equation 2 by 2 to eliminate x then add.
Since you are not given the following choices, by analyzing this series, it is a geometric progression because their common ratio is constant. Proofing that
4.8/(-3.2) = -1.5, also
-7.2/(4.8) = -1.5, and also
10.8/(-7.2) = -1.5
Just divide both sides by 2 because you want to do the opposite operation, to isolate x so if you do you get 80 so x = 80
