Question

write an equation in standard form for the line (-3,14) and (-6,9)

Answer 1

@charitynelson If we have two point (x1, y1) and (x2, y2)
equation of line passing through any point (x, y) is given as

\[\frac{y-y_2}{x-x_2}=\frac{y-y_1}{x-x_1}\]
Can you plugin (x1, y1)= (-3, 14) and (x2, y2)= (-6, 9) here?

Answer 2

woah im lost

Answer 3

is that how its set up jw

Answer 4

just plugin the values, substitute for x1, y1, x2, and y2

Answer 5

so would it be -3--6 and 14-9

Answer 6

ok, I'll show
\[\frac{y-y_2}{x-x_2}=\frac{y_2-y_1}{x_2-x_1}\]
(x1, y1)= (-3, 14) and (x2, y2)= (-6, 9)
\[\frac{y-(9)}{x-(-6)}=\frac{9-(14)}{(-6)-(-3)}\]
Can you simplify this ?

Answer 7

for the first one i got 3/2 and the second one i got -5/-3

Answer 8

@charitynelson notice that on the left side we have variables x and y, we can't reduce it further. However we can reduce the right side so we have
\[\frac{y-9}{x+6}=\frac{-5}{-3}\]
Can you cross multiply and simplify ?

Answer 9

are we cross multiplying the fraction and do i flip the -5/-3

Answer 10

yes. cross multiplying and yes you have to flip the fraction when you take it to the left side

Answer 11

can u show me what u mean by bringing to the left side because the wya i have it wrote idk just doesnt seem right

Answer 12

just a min

Answer 13

thank you

Answer 14

We can cancel both the negatives on left
\[\frac{y-9}{x+6}=\frac{5}{3}\]
Let's cross multiply
\[3(y-9)=5(x+6)\]
\[3y-27=5x+30\]
Can you simplify this from here?
bring variables to one side and constants on other

Answer 15

thank you sooo much and i had another question its quick he wants me to find slop of a line perpendicular to the graph of x-y=4

Answer 16

@charitynelson can you find slope of this line x-y=4?

Answer 17

no my teacher never explained well enough i know you use y = mx+b

Answer 18

yes, just bring the equation to this form
\[y=mx+b\]

Answer 19

so how do we plug that equation in

Answer 20

it's easy, change it to that form
\[x-y=4\]
\[x-4=y\]
or
\[y=x-4\]
now you can find m which is slope

Answer 21

this is the part the trows me off my teacher gives me the answer which is one but never explained

Answer 22

just compare both
\[y=mx+b\]
\[y=1x-4\]
m=1
b=-4

Answer 23

so for perpendicular how did he get -1

Answer 24

If two lines have slopes m1 and m2 and they are perpendicular, then
\[m_1\times m_2=-1\]
here m1 is 1
we need to find m2
\[1\times m_2=-1\]
you can find slope of perpendicular line from this

Answer 25

so how does m1 fit into beling -1 do we just subtract it or

Answer 26

no m1=1, which is the slope of given line
but m2, slope of perpendicular line =-1

Answer 27

so its the opposit of what ever slope is

Answer 28

if you have 2, then perpendicular line's slope =-1/2

Answer 29

so say for instnace it says to find slope of 2x-y=4

Answer 30

then would the slope be 1/2

Answer 31

or 2

Answer 32

Slope of this line, you have to compare from y=mx+c
\[y=mx+c\]
\[y=2x-4\]
m=2
c=-4

Answer 33

this is so confusing

Answer 34

it's just comparison, forget about reversing
I have
\[y=2x+4\]
I'll compare it yo y=mx+c
m=2 and c=4
so slope of this line =2

Answer 35

ok and then now the perpendicular part

Answer 36

for that
\[2\times m_2=-1\]
m2=-1/2
slope of line perpendicular to original line

Answer 37

oh i see it now ahhaha wow

Answer 38

cool

Answer 39

do u have time to help me with a more complicated problem

Answer 40

@charitynelson I have to go :( Sorry. I'll try to come later and help.