Answer: One unique solution.
Explanation:
When we have a system of linear equations like:
y = a*x + b
y = c*x + d
We have 3 possibilities:
1) There is only one solution, this happens when in the graph, the lines intersect at only one point.
2) There is no solution, in this case, the lines never intersect, this would be the case of two parallel lines.
3) We have an infinite number of solutions, this happens when both lines intersect in an infinite number of points, and this can only happen when both lines are the same line.
In this case, we know that we have two lines and they intersect in only one point, (-1, 2)
Then we have only one solution, and the solution is (-1, 2)