Question 98404
Y=-7X+8 (RED LINE) HAS A SLOPE OF -7.
THUS A PARALLEL LINE THROUGH (5,9) WITH A SLOPE OF -7 IS:
9=-7*5+b
9=-35+b
b=9+35
b=44 FOR THE Y INTERCEPT.
THUS THIS LINE EQUATION IS:
Y=-7X+44 (GREEN LINE) 
{{{ graph( 300, 200, -6, 5, -10, 50, y = -7x +8, y = -7x +44) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 50, of TWO functions y = -7x +8 and y = -7x +44). 
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A PERPENDICULAR LINE WILL HAVE A SLOPE OF 1/7 (THE NEGATIVE RECIPRICAL OF -7)
9=5/7+b
9-5/7=b
b=(63-5)/7
b=58/7 FOR THIS Y INTERCEPT.
Y=X/7+58/7 IS THIS LINE EQUATION (GREEN LINE)
{{{ graph( 300, 200, -10, 10, -10, 10, y = -7x +8, y = x/7 +58/7) }}} (graph 300x200 pixels, x from -10 to 10, y from -10 to 10, of TWO functions y = -7x +8 and y = x/7 +58/7).