some things to know
point slope form: for a line passing through (x1,y1) and the slope is m
y-y1=m(x-x1)
horizontal lines are y=constant
y=mx+b, m is slope and b is y intercept
the slope of the line that passes through the points (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)
1.
y-2=2/3(x-(-3))
y-2=2/3(x+3)
2.
find slope
(-2-3)/(6-(-4))=(-5)/(6+4)=-5/10=-1/2
a point isi (-4,3) and slope is -1/2
y-3=-1/2(x-(-4))
y-3=-1/2(x+4)
3.
yintercept of 2 means (0,2) is a point
find slope between (0,2) and (12,4)
(4-2)/(12-0)=2/12=1/6
a point is (12,4)
y-4=1/6(x-12)
4.
horizontal is y=something
(x,y)
(-2,-9)
we have y=-9
y=-9 is the equaiton
5.
y=-2x+3
y=mx+b
-2 is slope
a point is (-6,2)
y-2=-2(x-(-6))
y-2=-2(x+6)
