Find m or the slope of the two coordinates first.
M = y2-y1 / x2-x1
= 5 - (-1) / 1 - (-1)
= 6 / 2
= 3
Now that you have the slope, we can use the equation of a line which is :
y - y1 = m(x - x1)
Substitute any coordinate.
I'll go with (1, 5)
y - 5 = 3(x - 1)
y - 5 = 3x - 3
y = 3x + 2
And that's the equation in the slope intercept form or y=mx+b.
