what is the slope equation for the two points (.6,.5) and (.2,-.3)

(0.6,0.5), (0.2,-0.3).

m=(-0.3-0.5) / (0.2-0.6)=-0.8 / -0.4=2.

Y = mx + b = 0.5
2*0.6 + b = 0.5
b = 0.5 - 1.2 = -0.7
Y = 2x - 0.7.