What is the vertex of function f(x) = x2+12x

Aquadratic function f(x) has a turning point at (3,-7). what is the turning point of -f(x)?

Which expression is equivalent to? assume x > 0 and y > 0.

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?