1)3/8 *(-4)+5= -12/8+5= -3/2 +5=3,5
2)5/9 : (-1/3) -7= 5/9 *(-3)-7=5/3 - 7/1=5/3- 21/3=-16/3
3)2/5 *(-3) -4/5= -6/5 - 4/5= -10/5= -2
4)5/12 : 1/4 -(-1/3)= 5/12 *4 +1/3=5/3+1/3=6/3=2
5)1/2 * (-4) -5= -2-5=-7
6)4/9 : (-2/3) +1= 4/9 *(-3/2) +1= -2/3+1=1/3