The y-coordinate of the vertex of the function y = 2x^2-8x+c is 2. The value of c is... No Links please

Awater truck is filling a swimming pool. the equation that represents this relationship is y=19.75x where y is the number of gallons of water in the pool and x is the number of minutes the truck has been filling the pool.

Lucy spent $165 in december using a new credit card. in january, she began paying between $15 and $25 each month towards her account balance.

Can someone answer and tell me how to do this (will mark brainliest)