a) - 2 i 1/4*2 i 1/3= -9/5*7/3= - 3/5*7-21/5=4 i 1/2
b) ( -7 i 1/5):(-3 i 1/5)= 36/5:5/16=18:1/8=2 i 1/4
c) (-0,4)*(-5,07)=2,028
d) 0,056:(-0,7)=-0,08
