Answer:
The solution is the triplet: (a, b, c) = (-3, 0, 0)
Explanation:
Let's start with the second equation, and solving for "a":
a - b = -3
a = b - 3
Now replace this expression for a in the third equation:
2 a + b = -6
2 (b - 3) +b = -6
2 b - 6 +b = -6
3 b = -6 +6
3 b = 0
b = 0
So if b = 0 then a = 0 - 3 = -3
now we can replace a= -3, and b = 0 in the first equation and solve for c:
2 a - b + c = -6
2 ( -3) - 0 + c = -6
-6+ c = -6
c = -6 + 6
c = 0
Our solution is a = -3, b= 0 , and c = 0 which can be expressed as (-3, 0, 0)