How do i find the numerator and denominator?

Which expression shows the sum of the polynomials with like terms grouped together

1) you deposit $2,500 in an account that earns 4% simple interest. how much do you earn in eight years?

Ireally need subtract and simplify.(-y^2 – 4y - 8) – (-4y^2 – 6y + 3)show your work, ! i will mark you brainliest but you have to show your work.