<em />Is it for your kitchen sink or bathroom sink?
Answer:
Positive.
Step-by-step explanation:
When you see two negative signs directly next to each other (as shown in the given expression), it will become a positive sign:
7 - (-4) = 7 + 4 = 11
Positive is your answer.
* To be fair, even if there is only one negative sign, the answer will still be positive, however, I am assuming you are suggesting only the sign, and not the answer.
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Since the second equation gives a value for a, we can substitute it into the other equation to find a value for B.
Let's substitute b-2 into the first equation wherever there is an a.
a - 3b = 4
(b-2) - 3b = 4
b - 2 - 3b = 4
-2 - 2b = 4
-2b = 6
b = -3
Now let's find a by substituting -3 into either of the equations to find the value of a.
a = b - 2
a = -3 - 2
a = -5
So your solution set is (-5, -3)