Question

Indicate in standard form the equation of the line passing through the given points.

P(6, 2), Q(8, -4)

Answer 1

I know that I need to find the slope, in fact, I've already done that..

Answer 2

but how do I find the y-intercept?

Answer 3

y intercept 20
slope -3
http://www.wolframalpha.com/input/?i=find+equation+%286%2C+2%29%2C+%288%2C+-4%29

Answer 4

Hmm you dont need to find the intercept.

First calculate the gradient (skip this if you already have it)

Gradient is -3 ( skipping working)

SInce the line equation is y=mx+ c where m is the gradient and c is a constant.

Substitute one of the points in ( letz say P(6,2) ) and gradient= -3 into the equation.

2= (-3)6 + c
c= 20

SO eqn, of line is y=-3x + 20

Answer 5

so, If I were to fill in this blank _ x _ y _

Answer 6

x=20/3
y=20

Answer 7

what would I need to do? @tiaph that seems to make some sense, but I'm not sure.

Answer 8

oh yea silly me that is in fact calculating the y-intercept, discount what i said in the first line.

Answer 9

ok

Answer 10

Hmm what do you mean what you have to do? i shown you the workings? which part you don't understand?

Answer 11

Well
I have one blank before x and one after that, which is the one before y
_ x _ y

Answer 12

go to site http://www.wolframalpha.com/input/?i=find+equation+%286%2C+2%29%2C+%288%2C+-4%29 every step is given there

Answer 13

whr did you get the blanks?

Answer 14

From school, it is a fill in the blank :)

Answer 15

OIC, because in standard form of an equation of a line is given in the form Ax+By = C.

Note that previously i said y=mx+c is an alternative version, both are right though.

So in your case Ax+By = C.

Compared to the answer i give, y=-3x + 20
Rearrange to get,
3x+y=20

So A =3
B = 1
C=20

Answer 16

Oh, I see, thank you!

Answer 17

Np.