Question

y=mx+b

If b is did not cross the y intercept, for example, what would "b" be!?!?

Zero?

Answer 1

Don't really know what you are saying, but ...

If there is no y-intercept, then you must have a vertical line, and the equation would not take the form
y = mx + b
To have a vertical line, the m , or the slope would be undefined, which is not a numerical value

If b = 0, then your equation would be y = mx
but you would still have a y-intercept, namely the origin.

Answer 2

for example, if i graph (8,2) to (5,4), how would i write it in mx+b=y form?

Answer 3

Would b be 2? i am so confused!

Answer 4

first you need the slope m

m = (4-2)/(5-8) = -2/3

so y = (-2/3)x + b
but (5,4) lies on it, (we could use (8,2) )
4 = (-2/3)(5) + b
4 = -10/3 + b
b = 22/3

y = (-2/3)x + 22/3

I usually check my equation by using the point NOT used to find the equation.
e.g. for (8,2)
LS = 2
RS = (-2/3)(8) + 22/3
= -16/3 + 22/3
= 6/3
= 2
= LS
my answer is correct