algebra review!
posted by trixie on .
it says write the equation of the vertical line that passes through the point (7,3). what do i need to start it off?
find the equation for the line with undefined slope and passing through the point (1,2). what do i need to start that off?
what equation do i use to find the slopeintercept?
whats the pointslope form?

any vertical line has an undefined slope and always has the form x = c, where c is a constant.
All you need is a point, then simply state it as x = 'the x of the given point'
so for your first one : x = 7
for the second x = 1
slopeintercept form looks like this
y = mx + b, where m is the slope and b is the yintercept
e.g. y = 4x + 9
the slope is 4 and the yintercept is 9
the pointslope form is one of the best ways to find the equation of a straight line, given the slope and a point
e.g. given the point (5,3) and slope of 2/3, find the equation
y  (3) = (2/3)(x  5)
3(y+3) = 2(x5)
3y + 3 = 2x  10
you can now rearrange it to end up with any version they ask for. 
my last line should have been
3y + 9 = 2x  10