(1,5)&(8,5)
slope =(8-1)÷(5-5)
= 7÷0
the solution is undefined because any number which is divided by 0 is undefined
well there is 7x4, 14x2, and 28x1 of course.
9-b when b=8
9 -8 =1
9-b when b=-8
9 - (-8)
9+8
17
I'm not sure whether you meant b=8 or b=-8
'nine less than three times a number is negative twenty-one.'
