Question

Thomas works as an underwater photographer he starts at a position that is 15 feet below sea level he rises 9 feet then descends 12 feet to take a photo of a coral reef write and evaluate an expression to find his position relative to sea level when he took a photo

Answer 1

Sea level = 0 he started at -15, rose to -6, then went down to -18. Hope this helps. 

0-15+6-12=18