Slope-intercept form:
y = mx + b
"m" is the slope, "b" is the y-intercept (the y value when x = 0)
You need to find "m" and "b".
If you look at the graph, when x = 0, y is 1, so the y-intercept is 1.
y = mx + 1
To find "m", you can use the slope formula and find two points on the graph and plug it in, or you can use this:
Rise is the number of units you go up(+) or down(-)
Run is the number of units you go to the right.
If you look at the graph, from each point you go up 1 unit, and to the right 1 unit. So your slope is or 1
y = 1x + 1
y = x + 1