I need help with this ASAP

Yoku is putting on sunscreen. he uses 2\text{ ml}2 ml to cover 50\text{ cm}^250 cm 2 of his skin. he wants to know how many milliliters of sunscreen (c)(c) he needs to cover 325\text{ cm}^2325 cm 2 of his skin. how many milliliters of sunscreen does yoku need to cover 325 \text{ cm}^2325 cm 2 of his skin?

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

How to find the exponential function y=ca^x, with points (1,2) and (2,1)