Question 360551
Y=mX+b where m=slope & b= the Y intercept.
(3,4) and (11,18). 
m=(Y2-Y1)/(X2-X1)
m=(18-4)/(11-3)
m=14/8=1.75 ans. for the slope
4=1.75*3+b
4=5.25+b
b=4-5.25
b=-1.25 ans. for thew Y intercept.
Y=1.75X-1.25 (red line)
------------------------------
y=-3/2x +12
Y=-3x/2+12 (green line)
{{{ graph( 300, 200, -6, 5, -10, 15, 1.75x -1.25, -3x/2+12) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 15, of TWO functions 1.75x -1.25 and -3x/2 +12). 
1.75x-1.25=-3x/2+12
1.75x+3x/2=12+1.25
1.75x+1.5x=13.25
3.25x=13.25
x=13.25/3.25
x=4.077 ans for the x intercept
y=1.75*4.077-1.25
y=7.135-1.25
y=5.885 ans. for the Y intercept.
(4.077,5.885) is the intercept point.