The other tutor showed one way to graph the line, but I think you may just
be starting graphing lines from their equations, and you need this more
elementary method:
. That is in slope-intercept form
Some teachers teach it this way: "b" stands for "BEGIN" and "m" stands
for "MOVE". You BEGIN at the y-intercept, and then you MOVE from there,
as described below:
the slope is
and the y-intercept is
. The
y-intercept, b, means that we BEGIN where the line intersects the y-axis
at the point (0,b), which in this case is the point (0,5).
[That's where you "BEGIN". (Think of "b" as if it stood for "BEGIN".)
So we mark the y-intercept point (0,5), like this:
Now we MOVE from the y-intercept (0,5):
1. The slope is negative so this means from that point we go DOWN the NUMERATOR of
the slope. (When the slope is positive we go UP, but in this case we go DOWN).
The NUMERATOR of the slope,
is 2, and negative, (or you can consider
it -2, but either way we know from the sign, to draw the line segment DOWN from
the y-intercept). So we draw a line segment from the y-intercept (0,5) DOWN 2
units, from (0,5) to (0,3), like this:
2. Now from there, at the point (0,3), we draw a line TO THE RIGHT (ALWAYS to
the RIGHT) the DENOMINATOR of the slope, which is 3 units RIGHT. It goes from
the point (0,3) to the RIGHT to the point (3,3), like this:
Finally we draw a line, through the point we BEGAN at (0,5), and the point we
MOVED TO or ended up at, (3,3), and that is the graph of the line whose equation
is
.
You should LEARN:
1. that a line which has a POSITIVE number for its slope, always
leans to the RIGHT, and a line which has a NEGATIVE number for its slope
always leans to the LEFT, like this one.
2. that the GREATER the (absolute value) of the slope, the STEEPER the line.
3. if the slope is 1 or -1, the line is at an angle of 45o.
If the slope is a fraction or number less than 1 is not as steep as 45o and
if the slope is a fraction or number greater than 1, it is steeper than 45o.
Edwin