Write an equation for the line that passes through a point (2,4) with the slope 4?

The equation for a line in slope-intercept form
is:

y = mx + b

where m is the
slope and b is the y-intercept.  You are given m and a point.  You can use substitution
to find b.

Substitute 4 class="AM">`->` m, 2 class="AM">`->` x, and 4 class="AM">`->` y.

4 = 4 * 2 +
b

Now solve for b.

4 = 8 +
b

-4 = b

This is your
y-intercept.  Therefore the equation for this line
is:

y = 4x +
-4

This can be checked using a
graph:

src="/jax/includes/tinymce/jscripts/tiny_mce/plugins/asciisvg/js/d.svg"
sscr="-7.5,7.5,-5,5,1,1,1,1,1,300,200,func,4x-4,null,0,0,,,black,1,none"/>

Notice
that the line includes the point (2, 4).