How to find the domain of a function

The vertex of this parabola is at (-2,-3). when the x-value is -1, the y-value is -5. what is the coefficient of the squared expression in the parabola's equation?

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Hey hotel charges guests $19.75 a day to rent five video games at this rate which expression can be used to determine the charge for renting nine video games for one day at this hotel? pls