Line a is perpindicular to line b if the slope of line a is 1/8 what is the sllope of line b?

Since the slope would be perpendicular, you would reciprocate and change the sign of the current slope.

Let's start by reciprocating the slope:

1/8 - > 8/1

Now change the sign:

8/1 - > - 8/1

Note:

-8/1 also means - 8

Answer

The slope of line b would be - 8