2/100000 as a decimal is 0.000002. Count the zeros of the denominator. The amount of zeros is 6, so we add 5 zeros and then add the 2 which gives us 6 digits.
The slope of line u is 9/2; the line perpendicular to that is the opposite reciprocal...opposite sign and the flip of the fraction. The perpendicular slope is -2/9
