Slope-intercept form is y = mx + b, so to turn that equation into slope-intercept you'll need to get y alone
4x - 8y = 8 --- subtract 4x -8y = 8 - 4x --- divide by -8 y = -1 + (1/2)x --- reorder to match "mx + b" y = (1/2)x - 1
in y = mx + b, "m" is the slope and "b" is the y-intercept. so for part B, your slope is (1/2) and your y-intercept is (-1). take the sign with you.
for part C, you'll need to know point-slope form: (y - y1) = m(x - x1) you'll also need to be aware that "perpendicular" lines have a slope that is the opposite reciprocal of the original line.
the original slope is (1/2). change the sign to negative and form a reciprocal: your new slope is -2. plug that into your point-slope form
(y - y1) = m(x - x1) (y - y1) = (-2)(x - x1)
and lastly, plug in your given point: (1, 2)
y - 2 = (-2)(x - 1)
so, just to look a little neater without all of the work: A) y = (1/2)x - 1 B) m = (1/2), b = -1 C) y - 2 = (-2)(x - 1)
