Question

Consider the line 3x+5y=8
What is the slope of a line perpendicular to this line?
What is the slope of a line parallel to this line?

Answer 1

@Brill

Answer 2

So what is the slope of this line in the first place
I would put it into slope intercept form

Answer 3

-3/5 ?@Brill

Answer 4

so if it were parallel it would be -3/5 as well, since the slopes are the same. right?

Answer 5

Yep
You nailed the parallel part
A perpendicular line is always the NEGATIVE RECIPROCAL of the slope
So what would be the slope of a perpendicular line?

Answer 6

So for example the slope of a line perpendicular to a line with a slope of 2
Would be -1/2

Answer 7

would it just be 3/5

Answer 8

or 5/3?

Answer 9

Basically negative reciprocal is just fancy talk for multiply it by negative 1 and flip the numerator and denominator
So can you tell me what the slope is for certain now?

Answer 10

so 5/3!

Answer 11

Yup good job :)