Question

Which of the following is the equation of a line parallel to

4y=12x=5 that passes through (3,8)?

A.y=3x-2
B.y+4=8x
C.y+3x=2
D. y=4x-1

Answer 1

1. let that line be \(y=mx+b\)
2. parallel lines have identical slopes.
obtain \(m\) from the given line
3. this line passes throuogh (3,8) and hence, substitute \(x=3\) and \(y=8\) in the equation to find \(b\).

Answer 2

So wait it would be 8=3m+b

Answer 3

@electrokid

Answer 4

first find "m"

Answer 5

what is the slope of given line? (hint: ratio of y to x)

Answer 6

Ive never been good at slopes.. So how would I find M

Answer 7

original line:
\(4y=12x=5\)
now, \(m={y\over x}\)

Answer 8

so it would be 8/3
fraction wise not dividing

Answer 9

@electrokid

Answer 10

\[4y=12x\\{y\over x}=?
\]

Answer 11

8
-
3

Answer 12

\[12\over4\]!!!!

Answer 13

:)

Answer 14

do you see it?

Answer 15

Oh!!!! I see now

Answer 16

phew.
so, \(m={12\over4}=3\)

Answer 17

since our line is parallel to this line, its slope is the same

good so far?

Answer 18

Yup

Answer 19

nice
so, with the work till now,
we got
\[y=3x+b\]

so, we still need to find this "b"
how? -> we use the point (3,8)
plug in x=3 and y=8 in the above equation of line

Answer 20

what value do you get for "b"?

Answer 21

Ok so plugging it in

8=3(3)+b

Answer 22

perfecto

Answer 23

Okay so

8=9+b

it would have to be a negative right

Answer 24

-1

Answer 25

yes... it can be anything.. (positive or negative, dont matter)

Answer 26

good.
thats comples your answer
\[y=3x-1\]
what option says that?

Answer 27

none

Answer 28

I have one that says
y=3x-2

Answer 29

check the point and the original line eq.

Answer 30

it says
4y=12x+5

Answer 31

aha
but that is fine.. (slope depends on 'y' and 'x'.. const term gives you the y-intercept)
what about the point

Answer 32

I don't get what you mean..

Everything that is on my paper I put up on the description

Answer 33

math doesnt lie. so, check if you noted down the options and the point correctly.

Answer 34

among the options, only the (A) line is parallel to the given line but it does not pass through (3,8)

Answer 35

see if the point is (3,7)!!!!

Answer 36

Ohhh I accidentally put 8 instead of 7 my bad

Answer 37

see, told ya, math cannot lie, :)

Answer 38

Haha. My bad

Answer 39

So do we start all over or is it y=3x-2

Answer 40

not.. just the "b" part

Answer 41

plug in the (3,7) and find "b"

Answer 42

ok so it would be

7=3m+b

Answer 43

yes.. but you already have your "m" remember?

Answer 44

Ok so m stays the same

Answer 45

7=3(3)+b
7=9+-2
7=7
y=3x-2

Answer 46

Am i right or anywhere close

Answer 47

hold it....
you are "solving for b"
\[7=3(3)+b\\\implies7-9=b\\\implies -2=b\]

Answer 48

and now you have
\[\boxed{y=3x-2}\]

Answer 49

Ok can you help me with 2 more ones?