Question 387808
write in standard form equations of the horizontal line and the vertical line that pass through the point (-1,7).
Sol'n:

 For vertical:
  m=undefined,P(-1,7)
y-y1 = m(x-x1)
(y-7)/m = x+1
 0 = x+1 ----answer
 
 For horizontal:
  m=0,P(-1,7)
y-y1 = m(x-x1)
y-7=0(x+1)
y-7=0 ----answer