Question 322393
1.  Graph y=3/2 + 1

I'm assuming that this is {{{y=(3/2)x+1}}
Y int= 1
Slope={{{3/2}}}
{{{ graph( 300, 200, -5, 5, -5, 5, y=(3/2)x+1)}}}

2.  Find slope & y-intercept of each line 

12x-6y=9

First put into y=mx+b format
{{{-6y=-12x+9}}}
{{{(-6y)/-6=(-12/-6)x+9/-6}}}
{{{y=2x-3/2}}}

Slope= {{{2/1}}}
Y int= {{{-3/2}}}

3.  Solve using substitution method
2x+y=6
x-y=3

Solve for x in 2nd equation
{{{x=3+y}}}

Substitute (3+y) for X in 1st equation
{{{2(3+y)+y=6}}}
{{{6+2y+y=6}}}
{{{6+3y=6}}}
{{{3y=12}}}
{{{y=4}}}

Substitute 4 for Y in 2nd equation
{{{x-(4)=3}}}
{{{x=7}}}

(7,4)