# Math

posted by on .

Write an equation in a standard form of the line that passes through (3,1) and has a y-intercept of-2 .

• Math - ,

given the y-intercept of -2 implies you have a second point (0,-2)

so the slope is (-2-1)/(0-3) = -3/-3 = 1

You now have the slope and the y-intercept.
Can you take it from here ?

• Math - ,

x+y=-2 ?

• Math - ,

very close.

from the information so far we would have
y = x - 2

or x - y = 2

You can always check if your equation is correct by subbing in the given points.
notice for your equation and using (3,1)
we would get
3+1 = 2 ??

• Math - ,

How would you get a positive 2 though?

• Math - ,

I had better put my glasses on.

Good observation!

• Math - ,

thats ok, so would it be 4 ?

I now got -3x+y=-2

• Math - ,

no, I thought you understood when I told you it was x-y = 2.

Let's try it again:
2 points
(3,1) and (0,-2)
slope = (-2-1)/(0-3) = 1

then using y = mx + b
we have y = (1)x - 2
or -x + y = -2
or
x - y = 2

• Math - ,

ok thanks, sorry!