SOLUTION: Please help me I'm stuck :( Which is the equation of a line parallel to a line containing the points (-3, 1) and (6, 4) and passing throught the point (5, 2)?

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Question 358479: Please help me I'm stuck :(


Which is the equation of a line parallel to a line containing the points (-3, 1) and (6, 4) and passing throught the point (5, 2)?

Found 2 solutions by CharlesG2, Edwin McCravy:
Answer by CharlesG2(834) About Me  (Show Source):
You can put this solution on YOUR website!
Which is the equation of a line parallel to a line containing the points (-3, 1) and (6, 4) and passing throught the point (5, 2)?

slope-intercept form of a line is y = mx + b
where m is the slope,
and b is the y-intercept (vertical-intercept, or point (0,b))

m = slope = rise/run = (y2 - y1)/(x2 - x1)
m = (4 - 1)/(6 - -3) = 3/(6 + 3) = 3/9 = 1/3
parallel lines have the same slope

y = (1/3)x + b, solve for b by plugging in point (5,2)
2 = (1/3)(5) + b
2 = 5/3 + b
2 - 5/3 = b
1/3 = b (2 = 6/3)
y = (1/3)x + 1/3 (equation of line containing (5,2))

equation of line containing (-3,1):
1 = (1/3)(-3) + b
1 = -1 + b
2 = b
y = (1/3)x + 2

equation of line containing (6,4) will also be y = (1/3)x + 2:
4 = (1/3)(6) + b
4 = 6/3 + b
4 = 2 + b
2 = b
y = (1/3)x + 2


Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
Which is the equation of a line parallel to a line containing the points (-3, 1) and (6, 4) and passing throught the point (5, 2)?
 
First we'll draw the points that the first line goes through:
 

 
And then we'll draw that line.
 

 
We'll find the slope of that line using
 
m%22%22=%22%22%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29%22%22=%22%22%28%284%29-%281%29%29%2F%28%286%29-%28-3%29%29%22%22=%22%223%2F%286%2B3%29%22%22=%22%223%2F9%22%22=%22%221%2F3

The line parallel to that one must slope the same way, that is,
it must have the same slope.

 Now we'll use the point-slope formula with (x1,y1) = (5,2)

y-y%5B1%5D%22%22=%22%22m%28x-x%5B1%5D%29

y-2%22%22=%22%22expr%281%2F3%29%28x-5%29

Multiply both sides by 3:

3%28y-2%29%22%22=%22%223%2Aexpr%281%2F3%29%28x-5%29

3y-6%22%22=%22%22cross%283%29%2Aexpr%281%2Fcross%283%29%29%28x-5%29

3y-6%22%22=%22%22x-5

-x%2B3y%22%22=%22%22-5

x-3y%22%22=%22%225

To check, we'll plot the point (5,2) 



Then we'll get a couple more points
 
 x | y
 2 | 1
-1 | 0
 



Draw a line through those:



So the green line is parallel to the black line and it goes through (5,2).

Edwin