mat 101
posted by keith .
Equation for a line that passes through (6,26) and has a slope of 3
Equation for a line that passes through the points (5,5) and (10,20)
Equation for a line that passes through (9,25) and has a slope of 3.
Equation for a line that passes through (1,) and is perpendicular to the line 4x+6y=18.
Equatuion for a cirle with a radius of 4 and a midpoint at (2,2).

I already know how to do these. Try them yourself first and show me where you got stuck.
The first three can all be done substituting in
y = m x + b
where m is the slope.
For the fourth one, put the equation in form y = m x + b first
Then find m' = 1/m
That is the slope of a line perpendicular to the original one
then do y = m'x + b and substitute in your point, which you forgot to type the y coordinate for.
In the last one a circle equation is of form
(xk)^2 + (yh)^2 = r^2
where (k,h) is the center and r is the radius. 
y=mx+b
26=3(6)+b
b=26/18
b=13/9