Question

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)

Answer 1

solving by elimination I got rid of the a first by multiplying top by -1.
So I ended up with b being -3.......so the last one must be the answer

Answer 2

First, you want all the variables to be on one side:
a - 3b = 4
a - b = -2

Now you want to eliminate one of the variables, in this case a is easiest.

Subtract the second equation from the first and you're left with:
-2b = 6
so b = -3

Sub the value of b back into either of the equations and solve for x:
a - (-3) = -2
a = -5

So your answer is (-5,-3)