1. Diagonal formula1. Diagonal formulaDown diagonal minus up diagonal.det =-835-4|-8 3; 5 -4|D = 17down: -8 x -4 = 32up: 3 x 5 = 1532 - 15 = 17|-8 3; 5 -4|: (-8)x(-4) - 3x5 = 17.|-8 3; 5 -4|: (-8)x(-4) - 3x5 = 17.