Answer: y=x-1
Step-by-step explanation: if the line runs through the point (8,1) and then you followed the slope of 1 (rise of 1, run of 1) back to the Y axis, the line would run through -1 on the Y axis. The Slop-Intercept formula is y=mx+b, so replace m with your slope (1) and replace -1 for your y-intercept (where the line passes thru the y-axis)