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

a - 3b = 4 . . . . (1)
a = b - 2 . . . . . (2)
Putting (2) into (1), we have
b - 2 - 3b = 4
-2b = 4 + 2 = 6
b = 6/-2 = -3
From (1), a = b - 2 = -3 - 2 = -5
Hence, solution = (-5, -3)