Point slope form again
-3-9/3+1= -3
y+1=-3(x-9)
y+1=-3x+27
y=-3x+26
5+1/2+1=2
y+1=2(x+1)
y+1=2x+2
y=2x+1
For your system of equations you have
y={y=-3x+26}
y={y=2x+1}
There is a couple ways you can solve this. You could either use a subtraction method, or a substitution method. since they are both y = something i would just substitute one y in one or the other equation.
2x+1=-3x+26
5x+1=26
5x=25
x=5
So now you just plug in x = 5 for each quotation and you have your y's for both solution points
y=-3(5)+26
y=11
y=2(5)+1
y=11
So this works out nice, your solutions for the set of equations is (5,11) since they are the same points