Explain how the axis of symmetry is found if given a quadratic function either in standard form, y=ax^2 +bx+c,

or in general vertex form y=a(x-h)^2 +k

answer both with an explanation and steps so i can answer my teacher how i got them

Aaron invested a total of $4,100, some in an account earning 8% simple interest, and the rest in an account earning 5% simple interest. how much did he invest in each account if after one year he earned $211 in interest? select one: a. $200 at 8%, $3,900 at 5% b. $3,200 at 8%, $900 at 5% c. $900 at 8%, $3,200 at 5% d. $3,900 at 8%, $200 at 5%