The line through (-10, 2) which is perpendicular to the line y=8x+9 has slope -1/8 and y-intercept __?

The line is

L : (y-2)=-(1/8)(x-(-10))
or
L : y=-(1/8)x + 3/4
The y-intercept is the value of y when x=0.
Can you take it from here?