Question 921567: The equation of one line is y=(0.2)x + (-0.8). Write an equation for the line parallel to that line that passes through 4 of the equation y= -1/3x+4.
Answer by MathLover1(20849)   (Show Source):
You can put this solution on YOUR website! given: 
Write an equation for the line  to that line that passes through  of the equation 
first find: passes through of the equation
as you can see, that point could be ( ,) or y-intercept, since 
| Solved by pluggable solver: Finding the Equation of a Line Parallel or Perpendicular to a Given Line |
Since any two parallel lines have the same slope we know the slope of the unknown line is  (its from the slope of  which is also ).
Also since the unknown line goes through (0,4), we can find the equation by plugging in this info into the point-slope formula
Point-Slope Formula:
 where m is the slope and ( , ) is the given point
 Plug in  ,  , and 
 Distribute
 Multiply
 Add to both sides to isolate y
 Combine like terms
So the equation of the line that is parallel to and goes through (,) is
So here are the graphs of the equations and
 graph of the given equation (red) and graph of the line (green) that is parallel to the given graph and goes through (,)
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now see all three lines:
given line: ........red line
parallel line:  ........green line
, of the equation ........blue line
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