Question 608560
  <pre><font face = "Tohoma Ital" size = 3 color = "indigo"><b> 
Hi
 <u>Using the standard slope-intercept form for an equation of a line: {{{y = mx + b}}} , where m is the slope and b the y-intercept.</u>
{{{m =(y[2] - y[1])/(x[2] - x[1])}}}
X=0, Y=5...X=1, Y=2...X=2, Y=-1
(1,2)
(0,5) m = -3/1 = -3, |Yes, x is increasing by 1 and y is decreasing by 3 
y = -3x + b 
5 = -3·0 + b
5 = b  
{{{y = -3x + 5}}}  Green
x=2, y=-1, and x=3, Y=4.  
(3, 4)
(2, -1)  m = -5/-1 = 5
y = 5x + b
-1 = 5·2 + b
 -11 = b
{{{y= 5x-11}}}  Blue
x=-2, y=1 ... x=0, y=0,... 
 (0, 0)
(-2, 1) m = -1/2  |Yes, x is increasing by 2, y is decreasing by 1
 y = (-1/2)x + b
 0 = (-1/2)0 + b, b = 0
 y = {{{(-1/2)x}}} Purple   (Note: with negative slopes, lines slant to the left)
{{{drawing(300,300, -15,15,-15,15, grid(1),
graph( 300, 300, -15,15,-15,15,0,-3x + 5, 5x-11,(-1/2)x  ))}}}