SOLUTION: A line through (-5, -4) and (-1, y) is perpendicular to a line with slope -2/3. What is y?

Algebra ->  Linear-equations -> SOLUTION: A line through (-5, -4) and (-1, y) is perpendicular to a line with slope -2/3. What is y?      Log On


   

Question 1132572: A line through (-5, -4) and (-1, y) is perpendicular to a line with slope -2/3. What is y?
Found 2 solutions by solver91311, greenestamps:
Answer by solver91311(24713) About Me  (Show Source):
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The slope of a line is given by



So the slope of your line is



The slopes of perpendicular lines are negative reciprocals, that is to say

So set the calculated slope expression for your given line equal to the negative reciprocal of the given slope and solve the resulting equation for


John

My calculator said it, I believe it, that settles it

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The slope of the given line is -2/3, so the slope of a line perpendicular to it is 3/2.

From the first given point (-5,-4) to the second (-1,y), the change in x is +4 (from -5 to -1). Since the slope is 3/2, the change in y must be (3/2)(4) = 6. So the y value of the second point is -4+6 = 2.

ANSWER: y = 2