Write an equation in slope intercept form for a line that is perpendicular to y=9x+1 and has a y intercept at - 2

Y=mx+b

m=slope

b=yint

slopes of perpendicular lines multiply to - 1

y=9x+1

9 times what=-1

what=-1/9

yint=-2

too easy

slope=-1/9=m

ying=-2=b

y=-1/9x-2

The gradient of this line is 9 so the gradient of the perpendicular line is - 1/9 (the two perpendicular gradients must multiply to get - 1).

The equation of a line is y=mx+c

where m is the gradient and c is the y intercept

We can then just substitute values in:

y = - 1/9 (x) - 2