Question

PLEASE HELP ME!
AB<--> and BC<--> form a right angle at point B. If A = (-3, -1) and
B = (4, 4), what is the equation of BC<-->?
x + 3y = 16

2x + y = 12

-7x -5y = -48

7x -5y = 48

Answer 1

Basically youre trying to find the line perpendicular to AB.

Answer 2

So your first step is to find the equation of the line from the given coordinates.

Answer 3

ok how do I do that?

Answer 4

First find the slope of the line, can you do that on your own?

Answer 5

isn't it (7,-6)?

Answer 6

No, slope is expressed as \[\frac{ rise }{ run }\] and can be found using \[\frac{ y_1-y_2 }{ x_1-x_2 }\]

Answer 7

The y_1, y_2, x_1 and x_2 are place holders for the two points you were given. Like:
(x_1,y_1) (x_2, y_2)

Answer 8

Hint: The two you were given was (-3, -1) and (4, 4)

Answer 9

(-3, -1) (4, 4)
(x_1, y_1) (x_2, y_2)

Answer 10

so the slope is 5/7?

Answer 11

Yes! Good job. We are not done yet however.

Answer 12

So the standard form of a line is y = mx + b where m is the slope and b is the y-intercept.

Answer 13

For the sake of this problem we will ignore b.

Answer 14

The negitave slope will be perpendicular to our line.

Answer 15

So -5/7x + b = y

Answer 16

We move things around:
7x - 5y = -7b

Answer 17

And only one option's right side looks like this:
7x -5y = 48

Answer 18

that's not the answer though. I tried it and it said it was wrong