What help do you need? Do you know mathematically how to calculate the determinate of a 3x3 matrix by using determinates of associated 2x2 matrices? Can you define a 3x3 matrix in the program and populate it from data entered by the user? Can you obtain the required 2x2 matrices from the entered 3x3 matrix in the program? Given a 2x2 matrix, can you write the code to determine the determinant? Have you designed the program specifying required functions, algorithms etc etc?