SOLUTION: how do i write an equation of the line in standard form that passes through (1,2) and (3,16) i got: -7x+y=5 i put it in slope intercept then in standard.

Algebra ->  Linear-equations -> SOLUTION: how do i write an equation of the line in standard form that passes through (1,2) and (3,16) i got: -7x+y=5 i put it in slope intercept then in standard.       Log On


   

Question 661988: how do i write an equation of the line in standard form that passes through (1,2) and (3,16)
i got:
-7x+y=5
i put it in slope intercept then in standard.

Found 3 solutions by josmiceli, Alan3354, jim_thompson5910:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+%28+y+-+2+%29+%2F+%28+x+-+1+%29+=+%28+16+-+2+%29+%2F+%28+3+-+1+%29+
+%28+y+-+2+%29+%2F+%28+x+-+1+%29+=+14+%2F+2+
+%28+y+-+2+%29+%2F+%28+x+-+1+%29+=+7+
+y+-+2+=+7%2A%28+x+-+1+%29+
+y+-+2+=+7x+-+7+
+7x+-+y+=+5+
check:
does it go through (3,16) ?
+7%2A3+-+16+=+5+
+21+-+16+=+5+
+5+=+5+
does it go through (1,2) ?
+7%2A1+-+2+=+5+
+7+-+2+=+5+
+5+=+5+
OK

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
how do i write an equation of the line in standard form that passes through (1,2) and (3,16)
-----------------
Find the slope, m
m = diffy/diffx = (16-2)/(3-1)
m = 7
------
Use y = mx + b and either point to find b, the y-intercept
2 = 7*1 + b
b = -5
-----------
--> y = 7x - 5
================
Using determinants:
|x y 1|
|1 2 1| = 0
|3 16 1|
-------
x*(2-16) - y*(1-3) + 1*(16-6) = 0
-14x + 2y + 10 = 0
7x - y = 5

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
It should be

-7x%2By+=+-5

which converts to

7x-y+=+5