How do you get (5,2) ; (1,3) into slope intercept form

To obtain these 2 points within slope intercept form, what you would need to do, is first find the slope, using the formula for slope.

M = y2-y1/x2-x1 = 3 - 2/1 - 5 = 1/-4 or -1/4.

Knowing this, choose any one of the point and put it in the form y = mx + b.

Y = mx + b
2 = -1/4(5) + b
2 = -5/4 + b
2 = b - 5/4
b = 5/4 + 2/1
b = 5/4 + 8/4 = 13/4

Y = -1/4x + 13/4.