5 is the answer
I used my phone
A could be 2 while B could be 3, so -2a+3b turns into -4+9, which equals 5.
From what I know you can't really solve a a single equation with two-variables so it's just a matter of trial and error.
Just try plugging in a small number like 2 for a just to try it and you get 8b^2=72.
Divide everything by 8 to isolate b and you get that b^2=9.
Square root everything and you'll find that b=3. This is just one possible combination, I'm sure there are many more but this is obviously the one that was intended to be found.
Now that we know that a=2 and b=3 just plug them into the equation.
-2(2)+3(3)=?
-4+9=?
5
Sorry about having to use this ^ symbol, the equation maker is not working.
Answer:
There is not enough info to draw valid conclusion
Step-by-step explanation:
Hope this helps
Answer: A I think
Seems like the correct one
Answer:
B. 
; 
Step-by-step explanation:
According to the statement, we find that the following two conditions must be observed:
(Eq. 1)
(Eq. 2)
Since the difference between two even numbers leads to another even number. Hence, 
must be an even number and the correct answer is B.
