Two equations are given below:

a − 3b = 4
a = b − 2

what is the solution to the set of equations in the form (a, b)?

(−2, −2)
(−3, −1)
(−9, −7)
(−5, −3)

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)