Question 477441
Find an equation of the line having given the slope and containing   given point.  M=4 , (6,3)
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Here's one way:
Use y = mx + b and the point to find b
3 = 4*6 + b
b = -21
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--> y = 4x - 21
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Here's another way, useful when you're given 2 points:
Find a 2nd point by adding 4 to y and 1 to x
--> (7,7)
Use determinants:
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|x y 1|
|6 3 1| = 0
|7 7 1|
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x*(3-7) - y*(6-7) + (42-21) = 0
-4x + y = -21
4x - y = 21  same eqn in standard form