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Explanation:
All of this is shown in the diagram below.
Now follow the arrows in reverse. This shows that x = 1 leads to y = g(x) = -1.
Therefore, g(1) = -1 and x = 1 is the solution to g(x) = -1.
Side note: The equation is g(x) = 2x-3. We can replace g(x) with -1 and solve for x to get x = 1.