Line r passes through points (2, 11) and (10, 4). Line s is perpendicular to r. What is the slope of line s?

Respuesta :

Answer: 8/7

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Work Shown:

Use the slope formula to find the slope of line r
m = (y2-y1)/(x2-x1)
m = (4-11)/(10-2)
m = -7/8

The slope of line r is -7/8

Now we take the negative reciprocal. In other words, we flip the fraction and flip the sign from negative to positive.

Flip the fraction: -7/8 ---> -8/7
Flip the sign: -8/7 ----> +8/7

The slope of line s is 8/7

Note how multiplying the slope of line r (-7/8) and the slope of line s (8/7) yields -1. Multiplying any two perpendicular slopes leads to a product of -1. This is excluding vertical lines as the slope is undefined.