9th Grade Algebra 1

Find the slope of the line that passes through each pair of points.

( 4,6 ) ( 4,8 )

I got Y=x+8 then I did it again Y=x+6
I'm confuse
m=y2-y1/x2-x1 find m then b as in y=mx+b

Thanks if you took your time on this

You cannot follow that root of first calculating m as x2-x1 = 0 and division by zero is not allowed. It also means that m = tan theta = infinite hence the line makes an angle of 90 degrees with x axis and cuts x-axis at x = 4. Th equation to the line is: x = 4. y has all values belonging to the set R of real numbers and x is always equal to 4.

You can see the two points are at y = 6 and y = 8 on a vertical line through x = 4, so the slope is tan 90 or in other words, it is undefined, and the line equation is x = 4.

Now, to do it analytically, just like you did.....You are right

The slope formula given two points x1, y1 and x2, y2 is m = (y2 - y1)/(x2 - x1)

m = (8 - 6)/(4 - 4) = 2/0 = undefined, which tells you the line is vertical and the equation is x = 4

The line between (4,6) and (4,8) is a vertical line with a gradient(m) of infinity. The equation of the line is x=4. Sorry I couldn't be more help but the line has no slope as far as I can tell, it's a vertical line.

The slope is x and its 8-6/4-4 which is 2/0 which equals 2. The slope is 2. Y=2x+b =P

um, this is just x = 4

as x2 - x1 = 0 which means there is no rise in the x axis