Big book gre test 20 section 4 exercise 13

This might be a dumb question, but since the line is increasing, wouldn’t the slope be positive??
3
Thanks for the help!

You are right. The line is rising as you go from left to right, hence slope should be positive

But the correct answer is C (they are equal).

Yes, if you apply the slope formula \frac{y_2-y_1}{x_2-x_1} , you’ll get
\frac{0-b}{c-0} = \frac{-b}{c} , which is same as Quantity B

(Note: \frac{-b}{c} and \frac{b}{-c} are the same quantity)