Solve for the values of X and Y

Please I am struggling on this problem help!!!

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Jermaine has t subway tokens. karen has 4 more subway tokens than jermaine. raul has 5 fewer subway tokens than jermaine. which expression represents the ratio of karen's tokens to raul's tokens

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0