Question 360410
<pre>You will need to be able to solve a system of two equations
in two variables to do this problem.  If you don't know how
to do that post again asking how.

I will color-code the equations and their graphs:

{{{system(red(y=8-4x), green(y=5-x), blue(y=x-2))}}}

{{{drawing(400,400,-3,9,-3,9,
graph(400,400,-3,9,-3,9,8-4x,5-x,x-2), 
locate(1.2,4.2,A), locate(1.5,.5,B),
locate(7/2+.3,3/2+.3,C)



)}}}


We want to find the three vertices, the vertices A,B, and C
of triangle ABC  (points where two line intersect):

To find the vertex where the red and green lines intersect, 
solve this system:

{{{system(red(y=8-4x), green(y=5-x))}}}

Solve them by substitution and get (1,4)


To find the vertex where the red and blue lines intersect, 
solve this system:

{{{system(red(y=8-4x),  blue(y=x-2))}}}

Solve them by substitution and get (2,0)

To find the vertex where the red and green lines intersect 
by solving this system:

{{{system(green(y=5-x), blue(y=x-2))}}}

Solve them by substitution and get ({{{7/2}}},{{{3/2}}})


{{{drawing(400,400,-3,9,-3,9,
graph(400,400,-3,9,-3,9,8-4x,5-x,x-2), 
locate(1.2,4.2,"A(1,4)"), locate(.5,.5,"B(2,0)"),
locate(7/2+.3,3/2+.6,C(7/2,3/2))



)}}}

Edwin</pre>