Question

I just did a problem on point-slope form and when I was done with a question, I looked at the answer key for confirmation. At some points, I saw that the answer key had a much simplified version (y + 2 = 4x), whereas there are other times when the answer key said for me to leave it as like y + 5 = -(x - 4). Why is this the case?

Answer 1

@jim_thompson5910

Answer 2

I'd have to see the full problem

Answer 3

Okay so the problems are:
through (0, -2) and (-1, 2) for the answer of y + 2 = 4x

through (4, -5) and (0, -1) for the answer of y + 5 = -(x - 4)

Answer 4

The slope of the line through (0, -2) and (-1, 2) should be negative

Answer 5

oh yes sorry y + 2 = -4x

Answer 6

good, which is the same as `y+2 = -4(x-0)`

Answer 7

yes

Answer 8

they decided to simplify the `x-0` and replace it with just `x`

Answer 9

the slope of the line through (4, -5) and (0, -1) is not -1

Answer 10

why not?

Answer 11

oh my bad, I did -1-5 instead of -1-(-5). Yes the slope is definitely -1

Answer 12

ok

Answer 13

@jim_thompson5910

Answer 14

what other questions did you have?

Answer 15

point-slope is
y - y0= m(x- x0)

where m is the slope and (x0, y0) is the point
however , if either x0 or y0 is zero
you would simplify (*nobody* bothers to show add or subtract zero)
that is why
y + 2 = -4(x-0)
is written as
y+2 = -4x