Question 392341
y=mx+b (-1,_1) and (9,9) ( I not sure you write (-1,_1), y=-1 or 1) look like y=-1) I will use y=-1
m= 9-(-1)/9-(-1)=10/10 =1
y-9= 1(x-(1))
  y=x-1+9
  y= x+8