I was just learning about this. Okay,
First we need to plug in the values of the slope intercept form y = mx + b. b is the y-intercept so it is -2.
y = mx + -2.
Now lets find the rate of change or mx. the slope is 1/2 so the rate of change is 1/2. Lets plug in the value.
y = 1/2x + -2
The answer is A. Hope this helped!!