SOLUTION: what is the equation in the standard form of the line through (4,1) and (-2,3)?

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Question 150744: what is the equation in the standard form of the line through (4,1) and (-2,3)?
Answer by Electrified_Levi(103) About Me  (Show Source):
You can put this solution on YOUR website!
Hi, Hope I can help,
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what is the equation in the standard form of the line through (4,1) and (-2,3)?
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First, we need to find the slope of the line.
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We can find the slope by using the two points ( the slope is equal to +%28y2+-+y1%29%2F%28x2+-+x1%29+ or +%28y1+-+y2%29%2F+%28x1+-+x2%29+
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We will use the first equation
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(4,1)( x1 , y1 ) and (-2,3) ( x2 , y2 )
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+%28y2+-+y1%29%2F%28x2+-+x1%29+
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+%283+-+1%29+%2F+%28%28-2%29+-+4+%29+
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+2%2F+%28-6%29+
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It will reduce to +%28-1%29%2F3+
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- +1%2F3+ is the slope
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The slope intercept form of a line = +y+=+mx+%2B+b+ m = slope, b = unknown
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We can replace "m" with - +1%2F3+
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It becomes +y+=+%28-1%2F3%29x+%2B+b+
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We can find "b" by replacing "x" and "y" with one of our points
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(4,1)(x,y) and (-2,3) (x,y)
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We will use the first point, (4,1) (x,y)
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+y+=+%28-1%2F3%29x+%2B+b+
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+%281%29+=+%28-1%2F3%29%284%29+%2B+b+
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+1+=+%28-4%2F3%29+%2B+b+
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We will move +%28-4%2F3%29+ to the left
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+1+%2B+%284%2F3%29+=+%28-4%2F3%29+%2B+%284%2F3%29+%2B+b+
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+%287%2F3%29+=++b+
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+b+=+%287%2F3%29+
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We can replace "b" with +7%2F3+ in our equation
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+y+=+%28-1%2F3%29x+%2B+b+
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+y+=+%28-1%2F3%29x+%2B+%287%2F3%29+
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That is the slope intercept form of the equation, The standard form is +Ax+%2B+By+=+C+
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To get it to the standard form, we need to get rid of the fractions
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+y+=+%28-1%2F3%29x+%2B+%287%2F3%29+
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We will multiply everything by "3"
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+%283%29y+=+%283%29%28-1%2F3%29x+%2B+%283%29%287%2F3%29+
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+3y+=+%28-1%29x+%2B+7+
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+3y+=+%28-x%29+%2B+7+
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We will move (-x) to the left side
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+3y+%2B+x+=+%28-x%29+%2B+x+%2B+7+
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+3y+%2B+x+=+7+
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+x+%2B+3y+=+7+
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+x+%2B+3y+=+7+ is the standard form,
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+Ax+%2B+By+=+C+
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+%281%29x+%2B+%283%29y+=+%287%29+
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+x+%2B+3y+=+7+
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We can check by replacing "x" and "y" with the two points
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(4,1) and (-2,3)
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We will use the first point, (4,1) (x,y)
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+x+%2B+3y+=+7+
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+4+%2B+3%281%29+=+7+
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+4+%2B+3+=+7+
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+7+=+7+ True
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We will use the second point, (-2,3) (x,y)
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+x+%2B+3y+=+7+
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+%28-2%29+%2B+3%283%29+=+7+
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+%28-2%29+%2B+9+=+7+
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+7+=+7+ True
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Some other points to +x+%2B+3y+=+7+ = (1,2), (7,0), and (-8,5)
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+x+%2B+3y+=+7+ is the standard equation for the line
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Hope I helped, Levi