If eleven plus two equal one what does nine plus five equal?

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

Find the area of an equilateral triangle with a side of 6 inches

Segment an is an altitude of right δabc with a right angle at a. if ab = 2, squared 5 in and nc = 1 in, find bn, an, ac.