(6 1/4*8)*(2/3*18)-2 2/5*4=

(6 1/4 * 8) * (2/3 * 18) - 2 2/5 * 4 = 590 2/5
1) 6 1/4 * 8 = 25/4 * 8 = 25 * 2 = 50
2) 2/3 * 18 = 2 * 6 = 12
3) 2 2/5 * 4 = 12/5 * 4 = 48/5 = 9 3/5
4) 50 * 12 = 600
5) 600 - 9 3/5 = 599 5/5 - 9 3/5 = 590 2/5 = 590,4