You have a friend who needs to know how to use the slope and y-intercept; the rest below.?

Question

You have a friend who needs to know how to use the slope and y-intercept a) to write an equation and b) to draw a graph.

Give the detailed steps so that your friend can accurately write the equation as well as draw the graph from your description.
Thank you

Answer 1

The slope-intercept form is y = mx +b where m is slope and b is the y-intercept. So if slope = 3 and y -intercept is 4, the equation of the line is y =3x+4.

So plot the point (0,4) which is the y intercept.
Now find the x-intercept by setting y =0 and solving for x.
This gives 0 = 3x+4 so 3x = -4 and x = -4/3.
So plot the x-intercept at (-4/3,0). Now draw a line between these two points extending it as far as you like in either direction.

That completes the task.

Answer 2

y= mx+b is the standard equation of a line
let's say you have y= 2x+1:
the y-intercept is the point in the y-axis where the line will cross. So when you have 1 as your y-intercept, you start off at 1 on the y-axis, meaning your starting coordinates will be (0,1).
The equation of a slope is rise over run, so your 2 can actually be translated as 2/1. This means that you will have to move 2 points upward and 1 point to the right (from (0,1)). From the new set of coordinates ((1,3) if I'm right) connect to coordinates (0,1) and draw a line. So there you have it. :)

Answer 3

a) if you have 2 points (x1,y1) and (x2,y2) then solve as below to get your equation :
y-y1={(y2-y1)/(x2-x1)}(x-x1)
.......if you know the slope(m) and y intercept(c) then :
.......y=mx + c is the equation
b) get the x intercept as well from above and draw the line.
x intercept is when y=0 or (-c/m), the y intercept is of course c.