A=2/3×(2+3/4)
=2/3× (8+3/4 )
=2/3×11/4
=22/12
=22÷2/12÷2
=11/6
B=2/3×2+3/4
=4/3+3/4
=16+9/12
=25/12
C=1/2+1/3-1/6
=3+2/6-1/6
=5/6-1/6
=4/6
=4÷2/6÷2
=2/3
D=1/2÷1/3÷1/4÷1/5
=1/2×3÷1/4÷1/5
=3/2÷1/4÷1/5
=3/2×4÷1/5
=12/2 ÷1/5
=12÷2/2÷2 ÷1/5
=6÷1/5
=6×5
=30
