AB and BC form a right angle at point B. If A = (-3, -1) and B = (4, 4), what is the equation of BC? A. x + 3y = 16
B. 2x + y = 12
C. -7x − 5y = -48
D. 7x − 5y = 48

First we need the equation of line AB. Compute the slope through (-3,-1) and (4,4)

m = (y2-y1)/(x2-x1)

m = (4-(-1))/(4-(-3))

m = (4+1)/(4+3)

m = 5/7

This is the slope through points A and B, ie the slope of line AB.

To get the slope of line BC, we flip the fraction and change the sign.

Doing so has us go from 5/7 to -7/5. Note how 5/7 and -7/5 multiply to -1.

The slope of line BC is -7/5. Let m = -7/5.

Use (x,y) = (4,4) along with m =-7/5 to find the equation of line BC

y = mx+b

4 = (-7/5)(4) + b

4 = -28/5 + b

20 = -28 + 5b ... multiply every term by 5 to clear out the fraction

20+28 = 5b

48 = 5b

5b = 48

b = 48/5

With m = -7/5 and b = 48/5, we go from y = mx+b to y = (-7/5)x+48/5

The slope intercept form for line BC is y = (-7/5)x+48/5

Let's get this into standard form Ax+By = C

y = (-7/5)x+48/5

5y = -7x + 48 multiply everything by 5

7x+5y = 48 is one way to represent the equation in standard form

-7x - 5y = -48 ... your teacher has decided (for some reason) to multiply both sides by -1

-5y-7y=-48

Step-by-step explanation:

distance between BC (4,4) C(x,y)

BC is perpendicular on AB (perpendicular line has opposite reciprocal slope)

slope of AB=y2-y1/x2-x1=4-(-1)/4-(-3)=5/7

slope of BC=-7/5

now input the value of B (4.4) and C(x,y)

y=mx+b

4=-7/5(4)+b

b=4+28/5

b=48/5

y=-7/5x+48/5

5y=-7x+48

5y+7x=48 multipy by -1

-5y-7y=-48

the reason why your question keeps getting deleted because this is not a school related question : )

i will answer your question though.

i never tried church's

answer: there are x+184 pages in olivia's book.

step-by-step explanation:

let the total number of pages in the book which olive has already read be x.

then if olive has 184 pages left to read, then the total number of pages are in olive's book= pages she has read+pages she has left to read

therefore, the total number of pages in olivia's book=

hence, there are x+184 pages in olivia's book.