Question

What is the slope of a line that is perpendicular to the line whose equation is y=45x−3 A. −45 B. −54 C. 54 D. 45

Answer 1

B. -5/4

Explanation:

We're going to assume that you don't mean

y = 45x -3

which has a perpendicular line with a slope of -1/45.

Rather, we're going to assume that you mean

y = 4/5x -3

so that the slope of the perpendicular line is -5/4.

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Similarly, we're going to assume that the answer choices are supposed to represent fractions, so that the above slope matches choice B.

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If the slope of a line is m, the slope of the perpendicular line is -1/m. The reciprocal of a fraction is the fraction that has numerator and denominator swapped. -1/(4/5) = -5/4.