Question

Two equations are given below:

a – 3b = 28
a = b – 2

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

(–12, –10)
(–15, –13)
(–17, –15)
(–18, –16)

Answer 1

siince 2nd equation is already equal a, subsitute b-2 for a in the other equation

b-2-3b=28
-2-2b=28
add 2 to both sides
-2b=30
divide both sides by -2
b=-15
sub back
a=b-2
a=-15-2
a=-17

(a,b)
(-17,-15)

3rd choice