The thing that is tricky about the problem is visualizing it.
The equation y=x-1 has a slope of 1 and a y-intercept of -1.
If you have a y-intercept of 1 the point that corresponds is (0,-1).
If you move up 3 and right 2 you get a slope of 1.5. If you move up 2 and right 3 the slope is 0.66666.... We need a slope of 1.
Can you check to see if you wrote the equation right on the question?