(−2/3)(1/6) I need to know how to do fraction accurately

Answer && Step-by-step explanation:

Simple.

- 2/3  1/6 line up together, we already know end result is neg since only one neg sign

2*1 = 2

6*3 == 18

ans == -2/18

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

2nd one in the first row is correct