1) (7/15)-(3/40)-(1/24)=42/120=7/20
2) (24/10)*(1/3)-3=0,8-3= -2,2
3)(7/20)*(10/7)=0,5
4) -(22/10)*(5/11)= -1
5) (3/4)-(5/3)=(9/12)-(20/12)=-(11/12)
6) (4/9)-(5/12)+(3/4)=(28/36)=(7/9)
7) (11/6)* -(12/11)= -2
8)(7/9)*(3/7)=(1/3)
9) (0,5/-1)* (-2*3)= -0.5*(-6)= -3