Question 773946
{{{graph(150,300,-1,4,-8,2,2x-6)}}} It is a right triangle with legs (the perpendicular sides) measuring 3 units and 6 units.
You can take one leg as the base and the other as the height and use
area of a triangle = {{{base*height/2=3*6/2=highlight(9)}}}
 
How did I draw the line?
Since the x-axis (y=0) and the y-axis (x=0) are two of the sides, I knew one vertex of the triangle was at the origin.
I needed to know the other two vertices of the triangle, which would be the points where the line crossed the axis.
Those points are the x-intercept and y-intercept.
 
{{{system(y=2x-6,y=0)}}} --> {{{0=2x-6}}} --> {{{6=2x}}} --> {{{x=3}}} tells me one vertex is at {{{system(y=0,x=3)}}}, point (3,0). 
 
{{{system(y=2x-6,x=0)}}} --> {{{y=-6}}} tells me the other vertex is at {{{system(y=-6,x=0)}}}, point (0,-6).