How would you find the equation of a line?

Question

How would you find the equation of a line if you were given the slope and the x-intercept?

Answer 1

Use slope-intercept form.
It looks like this
y=mx+b
where m is the slope and b is the y-intercept.
you will need to solve for b to get an equation. Start by taking what you know and plugging it into the equation. You know m,x(use the x value of your intercept), and y(use the y value of your intercept, in other words since it is the x intercept, y must be equal to zero). After plugging these in solve for b. It is possible to have a negative value for b. Then take your b value and put it back into the equation with m and keep the x and y in as variables instead of a point, like when you were solving for b.

Answer 2

an equation of a line looks something like this..

y = mx + b
where m is the slope and b is a constant.

so.. if you're given the x-intercept.. that's the same as being given a point.. for example..

you're given slope=1/2, x-int=(2,0).. first, plug everything you know in.. use the (2,0) as your x and y..

0 = (1/2)(2)+b.. solve for b..
0 = 1 + b
b = -1

therefore.. y=(1/2)x-1 is the equation of that line.

Answer 3

Let's say the slope is 1/2 and the intercept is 3. That means the point (3,0) is on the line. Now we can use the following to obtain our formula for the line.

y-0 / x-3 = 1/2

cross multiply to get
2(y-0) = 1(x-3)
2y -0 = x-3

2y = x-3

x - 2y =3

Answer 4

The equation of a line is
y = mx + b,
where m is the slope and b is the y-intercept.
The x-intercept of a line, then, is
x = -b/m.
Call the x intercept a.
-b = ma
b = -ma
y = mx - ma
y = m(x - a)

More succintly, given the point (a,0) and the slope m
(y - 0)/(x - a) = m
y = m(x - a)

Answer 5

The x-intercept, by definition, is determined by making y = 0. Therefore, whatever your x-intercept is (Let's call it x[0]):

Into the slope formula, plug in your slope m, (x1,y1) as (0, x[0]) and
(x2, y2) as (x, y)

(y2 - y1) / (x2 - x1) = m

(y - x[0]) / (x - 0) = m

Solve for this and you get your question of your line. Note that you know what m and x[0] are, so you should get a final solution upon putting this in slope-intercept form.

Answer 6

there's a general formular

y = mx + c

where m is the gradient and c is a constant.

given the x coordinate you know that at y=0, x= the given value.
this means that u now have a coordinate of a point , say (2,0)
By substitution the point into the equation y =mx + c, the value of c can be found,

there u have it! the equation of the line!

Answer 7

The x-intercept is the value of x such that y is zero. Denote this value x0. So if we use the standard form
y = ax + b where a is the known slope, then

0 = a x0 + b
Solving this gives b = -a x0
Thus we have y = a (x - x0)

Answer 8

The formula y-y1 = m(x-x1) is the equation of the line passing thru (x1,y1) with slope m
The x-intercept is (x1, y1=0) = (x1,0)
The eqn for a line is y = m(x-x1) with y1 = 0

Answer 9

hmm...given the XINTERCEPT? strange...well lets see...

if you have graph paper, graph the x intercept, then graph the slope.