For my math homework we have to write the equation of the line with given slope and y-intercept then graph it?

Question

The slope is -2 and the y-intercept is (0,4).
I know that you have to write the equation of the line as :
y = -2x +4. or y=mx + b(right?)
But the next step is to graph it.
I understand how to graph the (0,4)
but how do you graph -2 (doing the rise and run) do you graph it as -2/1 or am i totally wrong.

Answer 1

Yes, that's the right idea. Just in case you're still confused;

OK< got your graph paper? make your x and y axis.
put a dot at your given intercept. (0,4) (when x is 0, y is 4. )
Now find your x intercept (if y = 0, x = what?)
0=-2x+4
-4= -2x
x=2.
So your x intercept is (2,0).
Make a dot at 2 on the x axis.
When you have 2 points you can make a line.
Draw a line through the 2 points.
I'm sure you don't need this much detail, don't be offended.

Answer 2

You are right!

Slope is defined as the rise or the change in the y values, which can be negative or positive, divided by the run, the change in the x values, which can also be positive or negative. Notice that -2 = -2 / 1 or 2 / -1. So you have two options for graphing the line from your given point, (0, 4). You can either go down 2 units (-2) and then over to the right 1 unit (+1), or you can go up 2 units (+2) and then over to the left 1 unit (-1). Both methods will get you the same line. Just to prove it to yourself that this is true, do both from that original point, (0, 4). Both of the new points will line up perfectly with it. If we go up from (0, 4), the next point, using the integers x = -1 and y = 2, which falls on the line is (0 - 1, 4 + 2) = (-1, 6). Going down from that point, we get (0 + 1, 4 - 2) = (1, 2). If you plot these last two points on graph paper, and then connect them with a straight line, you will find that the point (0, 4) falls exactly halfway between the two, and is on the same line.

We can verify that the two points we found have the correct slope by simply plugging them into the slope formula:

m = (y - y') / (x - x').

If we let (x, y) = (1, 2) and (x', y') = (-1, 6), then

m = (2 - 6) / [ 1 - (-1)] = -4 / 2 = -2 / 1 = -2, which is the required slope.

Answer 3

The y-intercept using fact the be conscious tells you is the intersection with the y-axis so the line will bypass by that element (0,4). What i do no longer trust is the (2,4) element. The equation of th line is y=-2x+4 thats the only you ought to graph. The formula to locate the unknown concepts is: y=mx+c (m the slope, c the y-intercept). you have the slope and the y-intercept that's 4 so the formula is right here: y= -2x+4 desire you recognize the thank you to graph it.

Answer 4

ok, starting @ (0,4)
First, RISE -2 spaces (aka sink 2), then RUN to the right 1.
Repeat procedure.
so the next points will be (1,2), then (2,0)
so on.
Going upwards, the poins would be (-1,6) then (-2,8)
To check the answers, plug any point into the y=mx+b so it would be:
y=mx+b
y=-2x+4
(4)=2(0)+4.....(substitute in the x and y values from the point.I used the y intercept coordinates.)
4=0+4
4=4.....Because it was solved equally, these coordinates work.
Good Luck, hope you get a good grade.

Answer 5

start at the point (0,4) and go down 2 right one repeatedly, then go back to (0,4) and go up 2 left one. This is because -2 is really -2/1. The top number tells you how much you go up or down, since this is negative you go down 2, and the bottom number tells you how much to go left and right, since this is positive you go right one.

Answer 6

You start at 4 then go down 2 over 1, then make a mark(like a dot or w/e). And if you have to, just keep going down 2 over one and make as many marks as you need.

Hope that helped