What is the vertex of the graph of f(x)= |x + 5| -6?

While scuba diving, rajeev dove to a depth of 12.6 feet below the surface of the water and then descended another 8.7 feet. what expression can be used to find rajeev's new position? 12.6 – 8.7 –12.6 – 8.7 –12.6 – (–8.7) 12.6 – (–8.7)

If i have one apple and give you the apple, how many apples do i have?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?