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Line L passes through the points (1, 1) and (7, 8). What is the slope of a line that is perpendicular to line L?

1.) -6/7
2.) -7/6
3.) 6/7
4.) 7/6

1 Answer

7 votes

When a line passes through the two points
(x_(1),y_(1)) and (x_(2),y_(2)) , its slope is given by the formula
m= (y_(2)-y_(1))/(x_(2)-x_(1))

In this question, a line L passes through the points
(1,1) and (7,8)

So, its slope is given by
m=(8-1)/(7-1)


m=(7)/(6)

When two lines are perpendicular, then the product of their slopes is -1.

Since, the slope of the line L is
(7)/(6) , so the slope of the line which is perpendicular to the given line L is
(-6)/(7)
as the product of
(-6)/(7) * (7)/(6)=-1.

User Dennycrane
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