SOLUTION: Here's another problem I have no clue how to do. The point P (3,2) is on line L. The sum of the x and y intercepts of line L is 12. Find all possible equations for line L in sta

Algebra.Com
Question 1063646: Here's another problem I have no clue how to do.
The point P (3,2) is on line L. The sum of the x and y intercepts of line L is 12. Find all possible equations for line L in standard form.

Found 2 solutions by Fombitz, rothauserc:
Answer by Fombitz(32388)   (Show Source): You can put this solution on YOUR website!
Start with the general equation of a line,

So you know (3,2) is on the line,


and the x intercept is,



and the y intercept is,



and their sum,


Combining with the previous equation,





Two solutions:


So then,




So the solution line looks like,


and


So,



So this solution line looks like,



Answer by rothauserc(4718)   (Show Source): You can put this solution on YOUR website!
The standard form of a line is
:
Ax + By = C, where A, B, C are integers and A > 0
:
if x = 0, then y = C/B, this is the y intercept
:
if y = 0, then x = C/A, this is the x intercept
:
For line L, we know that
:
1) C/A + C/B = 12
:
using point (3,2)
:
2) 3A + 2B = C
:
We have three points on Line L - (3, 2), (C/A, 0), (0, C/B)
:
slope(m) = (y2 - y1) / (x2 - x1) = ( 3 - 0) / (2 - C/B) = 3 / (2 - C/B)
slope(m) = (3 - C/A) / 2
:
set both equations for m equal to each other
:
(3 - C/A) / 2 = 3 / (2 - C/B)
:
from equation 1) we know that C/A = 12 - C/B
:
let C/B = k, then
:
6 = (3 - 12 + k) * ( 2 - k)
:
6 = (-9 + k) * (2 - k) = -18 +11k -k^2
:
k^2 -11k +24 = 0
:
(k - 8) * (k - 3) = 0
:
there are two possible values to consider
:
C/B = 8
C/B = 3
:
C/A + 8 = 12, C/A = 4 and C = 8B
4A = 8B
A = 2B
2Bx + Bx = 8B
2x +y = 8
:
C/A + 3 = 12, C/A = 9, C = 3B
9A = 3B
A = B/3
Bx/3 + By = 3B
x + 3y = 9
:
************
2x + y = 8
x + 3y = 9
************
:


RELATED QUESTIONS

Please help me with this!...I do not understand how to get the other answers without... (answered by stanbon)
A straight line L is perpendicular to the line 2/3 x+5/7 y=1 State the x and y intercepts (answered by math_helper)
The lines l and m have vector equations r = 2i-j+4k+s(i+j- k) and r= -2i + 2j+ k+... (answered by math_tutor2020)
The line l(1) has the equation y=3x. The line l(2) is perpendicular to l(1) and passes... (answered by mananth)
The lines l and m have vector equations r = 2i-j+4k+s(i+j- k) and r= -2i + 2j+ k+... (answered by ElectricPavlov)
How would I right an equation of the line perpendicular to the line l: y=-1/4x+2 and... (answered by granville)
Find equations in standard form of the line through point p that are a) parallel and... (answered by josgarithmetic)
If the equation of line L is ax + by = c, find its slope, both the x- and y-intercepts,... (answered by rothauserc)
If the equation of line l is ax + by = c, find its slope, x- and y-intercepts, and the... (answered by josmiceli,Theo)