You want to find the equation for a line that passes through the point (-1,5) and has a slope of 4.
First of all, remember what the equation of a line is:
y = mx+b
Where:
m is the slope, and
b is the y-intercept
To start, you know what m is; it's just the slope, which you said was 4. So you can right away fill in the equation for a line somewhat to read:
y=4x+b.
Now, what about b, the y-intercept?
To find b, think about what your (x,y) point means:
(-1,5). When x of the line is -1, y of the line must be 5.