Final answer:
The value of y is decreasing by 4 as the value of x increases by 1.
Step-by-step explanation:
To find the value of y when the value of x increases by 1, we need to use the given slope of -4. The slope of a line represents the rate of change of y in relation to x. Since the slope is -4, this means that for every increase of 1 in x, y will decrease by 4. Therefore, the value of y blank by blank is decreasing by 4 as the value of x increases by 1.