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Finding the Equation of a Line Given Two Points

STEP 2:  Now, use the point-slope formula with one of our points,
( 1 , 3 ), and m = -2 / 3.

* I picked ( 1, 3 ) since it didn't have any negatives -- it's just easier.


y - y1 = m ( x - x1 ) ... y - 3 = -( 2 / 3 ) ( x - 1 ) ... multiply by 3, which gives 3 ( y - 3 ) = 3 ( -2 / 3 ) ( x - 1 ) ... 3y - 9 = -2 ( x - 1 ) ... 3y - 9 = -2x + 2 ... add 9 to both sides, which gives 3y = -2x + 11

2x + 3y = 11 or y = ( -2 / 3 ) x + 11 / 3

YOUR TURN:

Find the equation of the line passing through the points ( -4 , 5 ) and ( 2 , -3 ).