SOLUTION: Can you pls help me find an equation of the line passing through the indicated pairs of points. I also need to expres my final answer in slope intercept form. Here is the probl

Algebra ->  Functions -> SOLUTION: Can you pls help me find an equation of the line passing through the indicated pairs of points. I also need to expres my final answer in slope intercept form. Here is the probl      Log On


   

Question 779455: Can you pls help me find an equation of the line passing through the indicated pairs of points. I also need to expres my final answer in slope intercept form.
Here is the problem: ((((1/2,3/5) and (- 1/4,2/5))))
Answer by AnlytcPhil(1810) About Me  (Show Source):
You can put this solution on YOUR website!
 ((((1/2,3/5) and (- 1/4,2/5))))

First we use the 
slope formula:
m = %28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29
where (x1,y1) = (1%2F2,3%2F5)
and where (x2,y2) = (-1%2F4,2%2F5)
Substituting in the slope formula

m = %28%282%2F5%29-%283%2F5%29%29%2F%28%28-1%2F4%29-%281%2F2%29%29 = %28-1%2F5%29%2F%28%28-1%2F4%29-%282%2F4%29%29 = %28-1%2F5%29%2F%28-3%2F4%29 = %281%2F5%29%2F%283%2F4%29 = 1%2F5÷3%2F4 = 1%2F5·4%2F3 = 4%2F15  

Next we use the point-slope formula:

y - y1 = m(x - x1) 

where (x1,y1) = (1%2F2,3%2F5)

y - 3%2F5 = 4%2F15(x - 1%2F2)

Now we solve for y:

Distribute on the right:

y - 3%2F5 = 4%2F15x - 4%2F15·1%2F2

              2
y - 3%2F5 = 4%2F15x - cross%284%29%2F15·1%2Fcross%282%29

y - 3%2F5 = 4%2F15x - 2%2F15

Add 3%2F5 to both sides:

y = 4%2F15x - 2%2F15 + 3%2F5 

The least common denominator for the last two terms is 15.
So we write 3%2F5 as 9%2F15

y = 4%2F15x - 2%2F15 + 9%2F15

y = 4%2F15x + 7%2F15  

Edwin