Question

A line has a slope of -4/5. Which ordered pairs could be points on a line that is perpendicular to this line?

Answer 1

Answer:

(5,4) & (8,-10)

Step-by-step explanation:

First step:

$y=mx+b$

You can use any number you want for b (I used 4)

$y=-\frac{4}{5} x+4$

Make x=0

$y=-\frac{4}{5} (0)+4$

$y=4$

Make y=0

$0=-\frac{4}{5} x+4$

Subtract 4 from both sides

$-4=-\frac{4}{5} x$

Divide both sides by $-\frac{4}{5}$

$x=5$

Second step:

In order to make a line perpendicular to another the slope of the second line will be the negative inverse of the first line. So  $m=-\frac{4}{5}$ will be $m=\frac{5}{4}$ for the second line.

Then you just need to repeat the process in first step to get the intercepts. (Again I used a random number like -10 for b)