-2 1/4 * (2 1/2 - 2 1/4)= -2 1/4 * (2 2/4 - 2 1/4) = -2 1/4 * 1/4 = -9/4 * 1/4 = -9/16 = -3/4
(-5/4 - 7/4) : (2 1/4 - 3/4)= -12/4 : 2 2/4 = -12/4 : 10/4 = -12/4 * 4/10 = -6/5 = -1 1/5
4 1/2 * (-2/3) * 2 2/3 : 18= 9/2 * (-2/3) * 8/3 : 18 = 24/3 : 18 = 24/3 * 1/18 = 4/9
5/3 : (-2 2/3) * 1/6 * 8/3= 5/3 : (-8/3) * 1/6 * 8/3 = 5/3 * (-3/8) * 1/6 * 8/3 = -5/18