Algebra: please check
posted by bart on .
Find the equation of a line that passes through the point (1,2)
and has a slope of 1/3. Show how you found the equation.
Would the equation be:
y2=1/3(x1)
Do I need to finish this? I am not sure how.

You set it up right. Don't forget your plugging in for x and y and you need to finish this.
So your equation would be
2=1/3(1)+b
B would be your unknown yintercept.
But this is not in slopeintercept form
So now you need to solve for b.
2=1/3(1)+b
2=1/3+b
subtract 1/3 from both sides you get
2 1/3=b
or
7/3=b
your equation would then be
y=1/3x2 1/3
or
y=1/3x7/3 
There are several ways to write the equation of a straight line.
The way troy showed you is the yinterceptslope form.
Your starting equation suggests that you have learned the pointslope form
continue from
y2=1/3(x1) by multiplying both sides by 3 to avoid fractions ...
3y  6 = x1
take everybody to the left side
x + 3y  5 = 0
usually we start with a positive x
x  3y + 5 = 0
This is the general form of the equation of a straight line, and it contains no fractions.