How can i find the equation of the axis of symmetry of a quadratic function? the function is: x^2+4x-5=y can someone show me step by step how to find the equation for the axis of symmetry?

Aclothing designer is selecting models to walk the runway for her fashion show. the clothes she designed require each model’s height to be no more than y inches from 5 feet 10 inches, or 70 inches. which graph could be used to determine the possible variance levels that would result in an acceptable height, x?