SOLUTION: Use the given conditions to write an equation for each line in point-slope form and slope-intercept form? X-intercept=4 y-intercept=-2 I tried to work this out and this is w

Algebra ->  Linear-equations -> SOLUTION: Use the given conditions to write an equation for each line in point-slope form and slope-intercept form? X-intercept=4 y-intercept=-2 I tried to work this out and this is w      Log On


   



Question 984266: Use the given conditions to write an equation for each line in point-slope form and slope-intercept form?
X-intercept=4
y-intercept=-2
I tried to work this out and this is what I got..
y=mx+b
0=m(4)+b
-b -b
-b=4m
y=mx+b
-2=0+b
b=-2
So then I would do...
4m=-2 and divide the 4 by 4 to get m alone and divide the -2 by 4 and get
m= -2/4, which is simplified to m= -1/2.
Its been a while since I have had a math class. Thank you for all your help!

Found 3 solutions by jim_thompson5910, josgarithmetic, MathTherapy:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
In y = mx+b, the b is always the y-intercept. So b = -2


y = mx+b

y = mx+(-2)

y = mx - 2


Now plug in the point (4,0) from the fact that the x intercept is 4.

y = mx - 2

0 = m(4) - 2

0 = 4m - 2

2 = 4m

4m = 2

m = 2/4

m = 1/2 ... take note that the slope is positive, not negative

-------------------------------------------------------

In the end, the equation in slope intercept form is y+=+expr%281%2F2%29x+-+2

In point slope form, the equation is y+-+0+=+expr%281%2F2%29%28x-4%29. You can use the other point to get y+%2B+2+=+expr%281%2F2%29%28x-0%29


Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
You can start with standard form.

ax+by=c
---
This part removed because of unknown mistake---

BETTER......
You can also start with slope-intercept form.
y=mx%2Bb, and you are given b.
y=mx-2
Now find the slope using the two intercepts.
m=%280-%28-2%29%29%2F%284-0%29
m=-2%2F4
m=-1%2F2
-
The equation should be highlight%28y=-x%2F2-2%29. The slope-intercept equation for those two axis intercept points.

Point-slope form?
Pick either intercept point and fill in y-v=m(x-u) and after substituting the values, keep in this format.
highlight%28y-%28-2%29=-%281%2F2%29%28x-0%29%29-----the y-intercept used here
or equivalently
highlight%28y%2B2=-%281%2F2%29x%29

Look again at the slope-intercept form found:
y=-x%2F2-2
Transform into standard form.
2y=-x-4
x%2B2y=-4

Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!
Use the given conditions to write an equation for each line in point-slope form and slope-intercept form?
X-intercept=4
y-intercept=-2
I tried to work this out and this is what I got..
y=mx+b
0=m(4)+b
-b -b
-b=4m
y=mx+b
-2=0+b
b=-2
So then I would do...
4m=-2 and divide the 4 by 4 to get m alone and divide the -2 by 4 and get
m= -2/4, which is simplified to m= -1/2.
Its been a while since I have had a math class. Thank you for all your help!
An x-intercept of 4 results in the coordinate point (4, 0)
A y-intercept of - 2 results in the coordinate point (0, - 2)
Using the slope formula, you'll find that m, or slope = 1%2F2, not -1%2F2
For point-slope form, you already know the slope: 1%2F2, and with one of the coordinate points: (4, 0),
the point slope form: y+-+y%5B1%5D+=+m%28x+-+x%5B1%5D%29 becomes: y+-+0+=+%281%2F2%29%28x+-+4%29, or highlight_green%28y+=+%281%2F2%29%28x+-+4%29%29
For slope intercept form, you already know the slope: 1%2F2, and the y-intercept, as represented by the
coordinate point, (0, - 2), so the slope-intercept form: y = mx + b becomes: highlight_green%28y+=+%281%2F2%29x+-+2%29