Question 80960
USING ANY SET OF POINTS USE THE FORMULA (Y2-Y1)/(X2-X1) TO FIND THE SLOPE THUS:
(4-3)/(2-1)=1/1=1 WHICH IS THE SLOPE.
NOW REPACE THE X & Y VALUES & THE SLOPE (m) IN THE LINE EQUATION Y=mX+b & SOLVE FOR THE Y INTERCEPT (b).
3=1*2+b
3=2+b
b=3-2
b=1
THUS THE LINE EQUATION IS 
Y=X+1
ANOTHER POINT IS (4,6)
{{{ graph( 300, 200, -6, 5, -10, 10, y = x +1) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = x +1).