what is the slope intercept form of (6,4) and (-6,-6)

Slope intercept form,

y = mx + b

(6,4), (-6,-6)
m = (-6 - 4)/(-6 - 6)
m = -10/-12 = 5/6

To find b, use (6,4)
m = 5/6
4 = 5/6 (6) + b
4 = 30/6 + b
4 = 5 + b
b = -1

Equation
y = 5/6 x - 1