Question 633413
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Hi,
Using the standard slope-intercept form for an equation of a line y = mx + b
  where m is the slope and b the y-intercept.
Line: passing thru  Pt(1, 2), with slope m = -1 
 y = -x + b
 2 = -1·1 + b   |Using ordered pair (x,y):(1,2)  to solve for b
 3 = b
 y = -x + b