I need these three answers pls

What is f(3) for the quadratic function f(x)= 2x^2+ + x - 12

Imogene invested $8,000 in a bank account that pays 8 percent simple interest at the end of each year. her friend invested the same amount in stocks where the growth of the investment is represented as 2,000 times the square root of 2 less than the time lapsed in years. if y1 and y2 represent the amount earned in dollars and t is the time lapsed in years, which system of equations correctly represents the situation?

Let f(x)=2x and g(x)=2x. graph the functions on the same coordinate plane. what are the solutions to the equation f(x)=g(x) ?me asap