(-21/6 -31/4): 23/5+ 2/3 *21/4- 5 1/6

(-21/6-31/4):23/5+2/3*21/4-5 1/6=-4 31/276
1) -21/6-31/4=-42/12-93/12=-135/12
2) -135/12:23/5=-675/276
3) 2/3*21/4=21/6
4) -675/276+21/6=-675/276+966/276=291/276
5) 291/276-5 1/6=1 15/276-5 1/6=1 15/276-5 46/276=-4 31/276

1) - 21/6 - 31/4 = - ( 42/12 + 93/12) = - 135/12 
2) - 135/12 : 23/5 = - 675/276 
3) 2/3 * 21/4 = 21/6
4) - 675/276 + 21/6 - 5 1/6 = - 675/276 + 966/276 - 31/6 = 291/276 - 1426/276 = - 1135/276 =
= - 4 целых 31/276