What is the slope of a line that is perpendicular to the line whose equation is 0.5x-5y=9

Question

A -5/9

B. -10

C. 1/10

D. -1/10

Answer 1

1) Turn this equation into slope intercept form y = mx + b. m - slope and b - y-intercept.

2) We need to take 0.5x - 5y = 9 and turn it into slope intercept form (solve for y).

3) I get -5y = -0.5x + 9. Then divide both sides of the equation by -5 to get y by itself. You'll get:

y = 0.1x - 1.8.

4) The slope is the number in front of your x variable, which is 0.1.

5) Lines that are perpendicular are opposite reciprocals of each other (Same thing as their products being -1)

6) Remember, the slope of the original equation is 0.1, so I need to figure out what I can multiply 0.1 by to get to -1.

7) Instead of me figuring that out, I can alternatively take -1 and divide by 0.1. When I do that, I get -10. What that means is that the slope of the line perpendicular to 0.5x - 5y = 9 is -10. Hope this helps!

Answer 2

The answer is b.

The equation is y = .1x - 9/5

The perpendicular line will have slope = -1/(.1) = -10