-3 1/4(2,4+4 3/4)= -23 19/80
2 4/10+4 3/4=6+(8+15)/20=7 3/20
-3 1/4×7 3/20=-13/4×143/20=1859/80=
= -23 19/80
-3 1/4(2,4+4 3/4)= -23 19/80
2 4/10+4 3/4=6+(8+15)/20=7 3/20
-3 1/4×7 3/20=-13/4×143/20=1859/80=
= -23 19/80