Aminer started at 8 feet above sea level and then traveled 23 feet straight down
into a mine shaft. What was the miner's
elevation after traveling down the mine
shaft?

-15 ft or 15 ft below sea level

Step-by-step explanation:

He started at +8 ft.

Then he went 23 ft down, that is -23 ft.

8 ft + (-23 ft) = 8 ft - 23 ft = -15 ft

-15 ft

graph b

step-by-step explanation:

one solution- graph a (clear intercepting point.)

no solution- graph b (they're parallel, there will never be a point of interception.)

infinite solutions- graph c (all points intercept.)