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)? (5 points)


(–2, –2)
(–3, –1)
(–9, –7)
(–5, –3)

Answer 1

a - 3b = 4
a = b -2

(b - 2) - 3b = 4
b - 2 - 3b = 4
-2b = 4 + 2
-2b = 6
b = 6/-2
b = -3

a = b - 2
a = -3 -2
a = -5

to check: a = -5 ; b = -3 ⇒ (-5,-3)
a - 3b = 4
-5 - 3(-3) = 4
-5 + 9 = 4
4 = 4