6 1/4:8-3 2/3*5 1/2+ 2 2/5*4 7/12

6 1/4:8-3 2/3· 5 1/2+2 2/5·4 7/12=1)6 1/4:8=25/4·1/8=25/322)3 2/3·5 1/2=11/3·11/2=121/63)2 2/5·4 7/12=12/5·55/12=114)25/32-121/6= 25/32-20 1/6=-20 1/6+25/32=-(20-59/96)=-19 37/965)-19 37/96+11=-19-37/96+11=(-19+11)-37/96=-8-37/96=-8 37/96